iiN^i«^i^S;i>ii^\^>^i^^\^s^\\\\\^^^^ Class Sfji^a. Book MXX.- Copyiight N° COPYRIGHT DEPOSrr Babcock Flask, Showing Fat in Neck (after Harrington) {Frontispiece) THE PRODUCTION AND HANDLING OF CLEAN MILK BY KENELM WINSLOW, M.D.; M.D.V.; B.A.S. {Harv?^ Formerly Instructor in Bussey Agricultural Itistitute and Assistant Professor in the Veterinary School of Harvard Utiiversity. Author of a textbook on Veterinary Materia Medica and Therapeutics, Chairman of the Committee on Milk . of the Washington State Medical Association^ etc. New York WII.I.IAM R. JENKINS CO. PUBLISHERS 851-853 Sixth Avenue fuBRAaY of CONSStSSj Two Copies KecetveO DEC 12 ;90f Ooyyneiii tntry ^^zlc (2- /f 7 CLi^SS'^ _XXc, Kj. COPY B. Copyright, 1907 By W11.1.1AM R. Jenkins Co. All rights reserved ^Registered at Stationers' Hall, London] Printed in the United States of America printed by the Press of Wiluam R. Jenkins Co. New York PREFACE The writer is a graduate in agricultural science, in veter- inary and human medicine, and has been connected with a laboratory in which is examined the milk supply of a large city, and finally has had considerable practical experience in the production and distribution of clean milk. These facts are simply mentioned to show that the book is written from various points of view. Much blame is attached to sundry persons engaged in vending milk, but the unfortunate farmer is apt to receive an unjust share because of the commonly unclean and there- fore unsanitary condition of most market milk. While city contractors and dealers may have much influence in instructing and requiring the farmer to live up to recognized standards of cleanliness, yet, after all, the chief responsibility lies with the consumer. The essential object in the clean milk crusade should be to awaken the public to the dangers of unclean milk and to emphasize the fact that it is impos- sible to produce and obtain clean milk except at unusual expense. When the public is sufficiently aroused to the evils of consuming unclean milk and evinces willingness to pay for clean milk, there will be no difficulty about its production. It is merely a question of supply and demand. PREFACE It is not generally known that the farmer sometimes receives but one-quarter of the retail price of milk (frequently but 2 cents a quart), and he can hardly be expected to undertake a considerably increased expenditure for the production of clean milk — this being the case. There is probably more interest being shown in this and other countries in a pure milk supply than ever before. For this reason it should be a comparatively easy task for any individual desiring to produce clean milk in any con- siderable community to find a sufficient patronage, particu- larly if the local medical profession is asked to assist, always providing that the proper standard is constantly and conscientiously maintained. The idea of financial return must be subordinated to this, and yet a reasonable profit can and must be had to sustain the required standard. The aim of this book is to provide a working guide for those pursuing or wishing to pursue one of the most whole- some, worthy and laudable undertakings — the production of clean milk. Most of the books at our command either touch the subject in a general manner or else describe special phases of it in detail. The attempt has here been made to cover the whole ground in as small compass as possible. That such an attempt must fall short the author is aware, as the topic of feeding cows alone (accorded but a chapter in this book) can only be fully treated in a large volume devoted wholly to this subject. Objection may be made to the recommendation of particular apparatus of certain manufacturers. But the PREFACE writer has been so desirous of making the book practical that it has been deemed essential to choose special appliances in order to avoid generalities and vagueness. While endeavoring to select the best, it does not follow that other appliances are not as good, or even better than those advised ; but the author can truthfully affirm that both he and his publisher are entirely free from the remotest financial interest in advertising any special dairy appliances. Such appliances are undergoing the most wonderful and rapid improvement, almost from day to day. Kenelm Winslow, CONTENTS CHAP. PAGE I. Germs in their General Relation to Milk . . i II. Composition of Milk and Cream and Their Pro- ducts 23 III. Milk Products 33 IV. Feeding for Milk 46 V. Housing and Care op Cows 57 VI. Handling of Milk and Cream 71 VII. Cost of Producing and Distributing Clean Milk i 10 VIII. Some Hints Concerning Milk Distribution . . 125 IX. Milk Inspection 134 Appendix — Plans of Barns, Milk Houses, etc 169 General Outline of a Scheme for the Control, Super- vision and Inspection of a City Milk Supply . . 198 Index 203 LIST OF ILLUSTRATIONS Frontispiece Fig I 2 General Shape of Bacteria . The Constituent Elements of Milk — Fat, Serum, Casein Sketch A — Two methods of ventilating a Dairy Farm Sketch B — Method of ventilating a Lean-to Stable Sketch C — Section of the Cow Stable of the Dairy Barn at the Wisconsin Experiment Station 3 Iron Milking Stool 3A The Gurler Milk Pail . 3B A Recent Improvement on the Gurler Milk Pail 3c Modification of Stewart's Milk Pail 4 The Conical Cooler 5 Star Cooler ..... 6 Tubular Cooler .... 7 Star Cooler ..... 8 Star Cooler 9 Star Cooler ..... 10 Trap Milk Strainer 1 1 Wash Sink ..... 12 Various Forms of Brushes . 13 Milk-Can Jacket .... 14 Star Side-Bar Filler 15 Star High- Pressure Cylinder 16 Star Sterilizer .... 17 Bottle Brush .... 18 Star Metal Wash Sink 19 Star Bottle- Washing Outfit . 20 Steam Heating Tee Page 4 24 62 63 64 72 73 73 74 79 80 80 81 ■82 83 84 86 87 88 89 90 92 93 94 95 95 LIST OF ILLUSTRATIONS Fig. 21 Glass Dairy Thermometer ...... 2 2 Machine for Chopping Ice used to pack about milk bottles 23 Banjo Conductor for carrying milk through a wall 24 Cylinder for conveying milk through a floor 25 Cream Cooler connected with Separator 26 Cream Bottle Filler 27 Bottle Carriers ........ 28 Car for conveying Carriers and Bottles 29 Car for conveying Carriers and Bottles 30 Wagon Box for carrying bottles on ice ... 31 Star Milk Bottles 32 Hand Separator for separating cream from milk . 33 Milk Wagon ........ 34 Milk Wagon ........ 35 Delivery Basket ........ 36 Small Babcock Machine, with other necessary paraphernalia 37 Eight-Bottle Babcock Machine ..... 38 Power Babcock Machine ...... 39 Pipette for making the Babcock test .... 40 Shows method of introducing milk into Babcock bottle with pipette in making the fat test .... 41 I cc. Pipettes enclosed in tubes for sterilizing 42 Flasks and Vials for quantitative bacteriological analysis 43 Two Burettes arranged for neutralizing culture media . 44 Petri Dishes . . . " . 45 Sketch showing ground plan of milk house owned by J. D Farrell, Esq. ....... 46 Rough sketch of ground plan of barn for forty cows (W. H Paulhamus, Esq.) ...... 47 Rough .sketch of ground plan of milk house (W. H. Paul- hamus, Esq.) ........ Page 96 97 98 99 100 lOI 102 103 104 105 106 107 126 127 128 142 143 143 144 145 149 150 152 153 179 181 183 LIST OF ILLUSTRATIONS PLATES I Yeksa Sunbeam (Guernsey) II Shadybrook Gerben (Holstein) III Pansy of Woodroffe (Ayrshire) IV Loretta D. (Jersey) . V Stable (J. D. Farrell, Esq.) VI Stable (J. D. Farrell, Esq.) VII Wash Room (J. D. Farrell, Esq.) VIII Milk Room (J. D. Farrell, Esq.) IX Interior of the Paulhamus Barn . X Bottle-washing Machine at the Paulhamus Farm XI Concrete and Cement Sterilizer, " XII The Improved " Drown " Stall . XIII The Burrell-Iyawrence-Kennedy Cow Milker XIV The Pulsator XV Illustrating the Hegelund method of milking D Dipper and Siphon for removing cream and milk respectively ..',.,.. T Colonies or collections of germs . . . . follows Page 170 170 172 172 178 180 180 180 180 182 184 186 188 188 192 132 156 CHAPTER I GERMS IN THEIR GENERAL RELATIONS TO MILK THE object of this book is to show the importance — nay, even necessity — of a clean milk production, and the practical methods by which it may be obtained. Heretofore milk has been regarded much in the same light as other articles of food, but It differs from them in many important respects. It is the only animal food which is commonly eaten in the raw state, and it forms the sole diet for human beings at an immature age, when they are least able to cope with the disorders which contaminated and dirty milk is liable to produce. Again — and this is the chief reason why milk needs especial care in its production — it always contains more or less germs, and, indeed, forms one of the most favorable foods on which germs grow. The common idea of germs appears to be that they are chiefly important in being the. cause of disease, and while some germs do produce disease — and occasionally those inhabiting milk which has not been properly cared for — yet they mainly interest the farmer on account of their powerful and enormous influence upon milk and its products. The chief aim of this book is to enforce on the farrner and dairy- man this one fact, that the One Essential in producing and handling milk is Cleanliness, and cleanliness means in this connection freedom from germs, so far as this is possible. 2 CLEAN MILK It would scarce be an exaggeration to say that all the trouble which arises in the endeavor to secure good milk or milk- products results from the contamination of milk with unde- sirable germs. Thus the proper taste, odor, color, consis- tency and keeping qualities of milk depend upon its comparative freedom from undesirable germs. Conversely, the souring of milk and faults in odor, color, consistency and taste depend almost wholly upon the presence of one or more varieties of germs. Moreover, the prevention of contamination of milk with miscellaneous germs is just as important in order to make the best products from milk, as it is to avoid disease in man. Thus the finest cream is only produced from milk in which germs are comparatively absent. Cream laden with miscellaneous germs has bad keeping qualities and often a faulty taste or odor. Most of the so-called faults of butter arise not from improper feeding of cows or from improper making or handling of butter, but from undesir- able germs which infest it. Among some of the more com- mon faults of butter are poor flavor, tallowy or oily butter, butter having a bitter, rotten or root-taste like turnips, rancid, mottled and moldy butter, and butter of unusual colors ; all of these faults have been proved to be due to the contamination of butter with germs which existed in the milk. While germs in milk produce changes in cheese which give rise to its proper consistency and flavor, yet it is only a certain type or types of germs which are desirable, and a general pollution of milk with germs of many kinds may wholly unfit milk for cheese making. It is essential that milk should be pure when employed for condensing, and, although germs are destroyed in the GERMS IN RELATION TO MILK 3 process, this is much more readily accomplished if the milk is clean in the beginning and the keeping qualities will be much better. Above all, when milk is sold for general con- sumption it must be pure — comparatively germ-free — to be wholesome, to bring a good price, to keep, and to fall within the legal requirements which will soon become gen- eral throughout this country. Heretofore, when milk was regarded in the same litrht as any other food, the law required simply that it should not be adulterated and that it should contain a quantity of food-constituents equivalent to the minimum standard in force. Now, however, it has come to be realized that of the two the cleanliness of the milk is an hundredfold more important than its food value. While a milk poor in fat may mean a certain loss of nutriment to one using it, the contamination of milk with certain germs may be a matter of life and death to the consumer — particularly if an infant. The sooner the farmer and dairyman realize that the secret of success in the making of milk and milk-products is clean- liness — and by cleanliness we mean essentially methods to prevent the entrance of germs into milk — the better will it be for them and for everyone. Germs, or, as they are more technically termed, bac- teria, are the most minute forms of plant life we know. They occur in various shapes, but chiefly in the form of either rods, round cells or spirals. When seen through the microscope they present somewhat the appearance of minute pencils, billiard balls or cork-screws, according as they be- long to one or the other of these three types. In masses of thousands they may be visible to the naked eye as specks like mold, but singly they can only be seen with a com- pound microscope magnifying more than 500 times. The 4 CLEAN MILK most common of all varieties of germs in milk are those which cause it to sour — the lactic acid bacilli (the bacilli are the rod or pencil-shaped germs), and these are about 3-25,000 of an inch long and 1-25,000 of an inch broad. Germs grow on vegetable and animal matter, but not in the tissues or cells of living animals or vegetables, althougTi they are found on all parts of them exposed to the air. Germs are, in fact, everywhere — in the air, in water, in soil, on the skin and in the digestive canal of animals and on the sur- face of plants and in dust. Professor Conn has found as many as 200 different kinds of germs in milk alone. Germs. Fig. I. 2^ C General shape of bacteria, a, spheres ; b, rods ; c, spirals. (After Conn.) 0^0 a O propagate by dividing into two equal parts — more usually — which form new individuals. The time required for a germ to mature and form a new germ may not be more than twenty minutes. Germs also multiply by spores — that is, small, round or egg-shaped bodies appear within the mature germ and these later break loose and develop, under favorable cir- cumstances, into full-grown germs again. Germs which increase in this manner are much more difficult to kill, for in the spore stage they often defy prolonged heat, even at the boiling temperature, and also cold at or below freezing and dryness, as dust, in v ■ 'ch they may exist for years.- GERMS IN RELATION TO MILK 5 To show the possibilities in the way of multiplication, it has been calculated that a single germ, under favorable circum- stances, may within twenty-four hours produce over sixteen millions of progeny. Germs, however, depend upon certain conditions for their growth ; otherwise they would crowd all other life off the globe. Besides organic matter to feed on, the chief circumstances limiting their existence are heat and moisture. Germs usually do not grow at a temperature below 39*^ or above 140° F. Freezing does not necessarily destroy germs — as, for instance, the germs of typhoid fever have remained alive in ice for a period of three months — but this temperature checks their growth and many kinds of germs are killed by it. Ice water is therefore comparatively free from germs. The most favorable temperature for the growth of disease germs is that of the animal body — from 98^ F. to 103^ F. — while most other germs multiply most readily between the temperatures of 59^ F. and ']']'^ F. This knowledge is of the greatest importance in the care of milk and teaches us that the chief essential consists in cooling it immediately to a low temperature — 40^^ F. to, 50^ F. — and keeping it at this temperature thereafter till consumed. The number of germs in milk is always estimated as that number contained in a cubic centimeter of milk. A •cubic centimeter represents a cube holding a quantity of hquid equivalent to about one-quarter of a teaspoonful, or sixteen drops of water. If milk is kept at below 50" F. for 24 hours there is not only not an increase but generally a decrease in the number of germs, and the same usually holds good for milk kept 36 hours below 45*^ F. After 36 hours, when milk is kept at 40° F., there is an increase in the number of germs. Dr. Park found in a sample of milk 6 CLEAN MILK containing only 3,000 germs in the cubic centimeter, that after 24 hours at 42° F. it contained 2,600 germs ; after 48 hours 3,600 germs ; and after 96 hours 500,000 germs to the cubic centimeter. The number of germs in milk kept at 32*-^ F. lessens from day to day. When milk is kept at higher temperatures the germs multiply rapidly and it sours and deteriorates correspond- ingly. It has been shown that very clean milk (containing but 3,000 germs to the cubic centimeter^, if kept for 24 hours at 60*^ F., held 180,000 germs; if kept at 86^ F. for 24 hours it contained 1,400,000 germs; and at 94^ F. the germs multiplied so tremendously that at the end of 24. hours the same milk contained 25 billion germs per cubic centimeter. All germs require some moisture in order that they may actually grow, but they may exist in large quantities — for a longer or shorter time — in dust. Some require air for their existence, others do not. Sunlight is one of the most powerful enemies of germs, since few will thrive in sunlight, especially in the presence of plenty of air. This explains the value of sunning dairy utensils and of permitting the sunlight to enter freely into the barn and dairy. Some germs grow more readily in sub- stances having an alkaline or neutral reaction ; others, as those which cause milk to sour, flourish in an acid medium, providing the acidity is not too great. The most potent factors in destroying germs are intense heat and cold, sunlight and chemicals. A temperature varying from 140*^ to 158° F. will kill most germs — if con- tinued long enough or repeated at frequent intervals. Milk treated by continued, intermittent heating at 140^^ F. has been kept for years without changing, owing to the destruc- GERMS IN RELA TION TO MILK 7 tion of germs (and ferments) in it. As the time required for the destruction of germs at this temperature is too great for practical dairy purposes, a temperature of 165^ F. is usually applied for either killing or checking the de\elop- ment of germs in milk. Heating milk with this object in view is called technically pasteurization, after the great originator of the process. If properly done for twenty min- utes, pasteurization kills most of the germs in milk and this is the best way to obviate the dangers of dirty milk for human consumption — more particularly in the case of infants. There are certain drawbacks to the process, how- ever. If the milk has been kept long before heating, poisons may form in it which the heat will not destroy. Many medical authorities believe that milk thus heated is less digestible, but this is an unsettled matter at present. There are certain substances present in cows' milk exactly resem- bling those which bring about the digestion of food in the stomach and bowels of man and animals. These chemical substances in milk or in the digestive organs are called fer- ments. They appear to aid the digestibility of milk, particularly in infants, and are destroyed by heating milk over 179° F., or at a lower temperature if the milk is repeatedly heated. It is generally accepted, however, that babies will not thrive so well on pasteurized milk for long periods, as on clean, unheated milk, and occasionally develop malnutrition, anemia, rickets and scurvy. The last may be prevented by feeding infants a small amount of orange juice daily. The simplest method of home pasteurization consists in pouring a quart of milk into a two-quart glass preserve jar and placing the jar with the milk in it on a flat, thin piece of wood (to prevent breaking of the jar by heat) in an open kettle. Warm water is then poured into the kettle so that it 8 CLEAN MILK will rise to almost the level of the milk In the jar and the kettle Is set upon a stove. When the water in the kettle begins to boil the kettle is removed to the back or side of the stove — where it will receive but little heat — for twenty minutes, and then the bottle is taken from the kettle and placed in a refrigerator. As I have observed, in pasteur- ization done on a large scale for market purposes in Seattle, the result has been a farce other than it enabled the milk- man to keep the milk for perhaps twenty-four hours longer than it would have otherwise kept sweet. The pasteuriza- tion of the market milk was only done for three minutes, possibly because the machine — which permitted of a cpntin- uous flow of milk through it — was not competent to do the work properly, but also because thoroughly pasteurized milk has a cooked taste and cream does not rise readily from it, much of the fat remaining in the skim milk. The pasteurizers having a large chamber, in which the milk may be retained for the required time at the proper temperature, are preferable. Short pasteurization prevents milk from souring quickly because the germs which cause milk to sour are those most readily succumbing to heat. The general effect of short pasteurization is simply to check — for a longer or shorter time — the growth of germs. They are retarded in their development, not killed. Disease germs are not destroyed at all in the process. Experiments which 1 have conducted with the pasteurized milk of the general market showed that while containing but 15,000 germs to the cubic centimeter, soon after emerging from the pasteurizer on the delivery wagon, in twenty-four hours the same milk con- tained several million germs to the cubic centimeter. Drs. Bergey and Pennington found much the same result in Philadelphia ; that raw and recently pasteurized milk con- GERMS IN RELATION TC MILK 9 tained respectively 1,260 and 12 bacteria, but, at the end of 72 hours, the numbers were 17,000,000 and 148,000,000 ^erms. Also the harmless lactic acid germs of raw milk are killed by heat, and the more dangerous germs from dirty bottles, corks and dust contaminate the improperly pasteurized milk. I have, however, pasteurized fresh, clean milk for twenty minutes and exposed it at mild spring weather temperature for nineteen hours in a sealed bottle with the result that it was absolutely free from germs at the end of that time. If pasteurization is done thoroughly the lactic acid bacilli (sour milk germs) are destroyed and so the milk does not sour but putrefies when it ages. Pasteurization prevents milk from being properly cur- dled by rennet and so unfits milk for cheese-making. Pas- teurized milk or cream may be used to advantage for butter- making when the lactic acid germs are added In the form of sour milk, known as a "starter," which will be described later. If we must have dirty milk, pasteurization is the best remedy for this unhappy state of affairs, but it may well prove undesirable to thus remove the incentive to dairymen to produce clean milk. If done at all for the market, it should be done thoroughly by heating the milk for twenty minutes to 1650 F., followed by rapid cooling.* If milk is not cooled down to a low point after pasteurization, spores will develop which have escaped destruction on account of their great resistance to heat, and these will result in germs which, while not souring milk, act on the casein to cause it to curdle and perhaps become poisonous and putrid. In Europe pasteurization of milk is much more common than in this country, since ice is in less common use. In Den- mark it is required by law, so that tuberculosis may not be spread when skim milk Is returned from the creameries and * Pasteurized milk wliich is sold for general consumption should be always marked as such, iu order that infants shall not be harmed by its use. lO CLEAN MILK fed to calves. This custom might well be imitated in the United States, since the young stock are not only protected from disease, but the keeping quality of the skim milk is so much improved. A higher temperature than 165° F. gives the milk a boiled taste and alters its composition to some extent. Steam or boiling water are used to destroy germs in or on dairy utensils. Chemicals find little use as germ-destroyers in a pro- perly conducted dairy or farm. They may be employed to some extent in the barn (as lime scattered on the floor), or in case milk products become faulty through some con- tamination with special germs in the stable or dairy, when general disinfection is in order. The employment of the various preservatives under the trade names of Freezine, Iceline, Preservaline, Milk Sweet (all containing from two to five per cent, of formaldehyde), and others containing boric acid, as Dry Antiseptic, Preserving Salts, "A" Pre- servaline, Cream Albuminoid, Patent " M " Preservaline and Ozone Antiseptic Compound, are employed to keep milk from souring without the use of ice or cleanliness by killinor or checkincr the crrowth of crerms in milk. Their use is contrary to law and detrimental to the consumer's health, especially when employed, as they usually are, in a careless way, without regard to what the effect of a con- siderable amount of the chemical might be. Thus the following instance is related in the Year Book of the Department of Agriculture for 1900 of a case where a preserving fluid was first added to the milk by the farmer, then by the collector of the milk, again by the wholesale dealer, and finally the fourth dose by the retail dealer. If it were impossible to produce clean milk or to pre- serve it with ice, and if preservatives could be used properly GERMS IN RELATION TO MILK ii in a harmless dose, their employment might be permitted, but such is not the case. Significance of Gcrnis in Milk The growth of large numbers of germs in milk causes it to deteriorate because they remove nutriment or alter the milk chemically and thus lessen its food-value. Ordinary market milk, which is overrun with germs, loses much of its value as food after it is twenty-four hours old. The ideal result would be reached if milk could be withdrawn from the cow absolutely free from germs. This might be pos- sible if germs did not enter the udder in the air through the opening in the teat and find their way into the cavity or milk-cistern in the lower part of the udder. As the milking proceeds the germs in the milk-cistern and teat are washed away so that the latter part of the milk withdrawn is often absolutely free from germs until contaminated with the out- side air. Occasionally germs may persist in milk throughout milking, and the strippings may contain as many as 500 germs to the cubic centimeter. If the latter part of the milk is withdrawn through an absolutely clean milking tube into an absolutely clean bottle, it will often be wholly with- out germs, and may keep sweet for months or years if it does not come in contact with the air. Such painstaking cleanliness as is necessary to make this experiment suc- cessful, is not of course practicable in actual dairy work, since it is not economically possible to throw away a laro-er part of the milk nor to withdraw milk so that it will not come in contact with air.* Therefore, under any ordinary conditions a certain number of germs must inevitably be present in the cleanest milk — perhaps 200 to 4,000 as the least number to the cubic centimeter. * Since writing the above the use of the milking machine (see p. 189) makes withdrawal of milk without exposure to air practicable. 3 2 CLEAN MILK Then, if the milk is immediately cooled to 40° F. and retained at this temperature, the number of germs will lessen until it is thirty-six hours old. The presence of many thousand germs to the cubic centimeter in milk freshly withdrawn indicates filthiness of the cow, milker or surroundings. The existence of a great variety of germs in milk sev- eral hours old signifies contamination of the milk with filth also, because in clean milk only one kind of germs (lactic acid bacilli) are found very numerous after many hours. While the .mere fact that milk contains a vast number of germs is not a sure proof of its unwholesomeness — because the commonest grerms in milk are harmless and because milk may contain but a few germs and these may be the cause of dangerous disease in man — yet the estima- tion of the number of germs in milk is to-day the best method we possess for determining its purity. Ordinary market milk contains as many germs as sew- age, and unusually dirty milk contains more germs than sewage was ever known to hold. This is, however, not at all a fair comparison, for while sewage is likely to contain all sorts of germs of disease, the germs in dirty milk are mostly not disease-germs. We may consider the influence of germs in milk under two heads : i. The effects of germs on milk and its products. 2. The influence of eerms in milk on the consumer. I. The Effects of Germs on Milk and Its Products. — All fermentation and putrefaction or.rotting, anywhere and of anything, are due to germs. Germs are the great disintegrating agencies in the world ; they tend to break up complex, natural constituents GERMS IN RELATION TO MILK 13 in milk and Its products int.o simpler bodies. The com- monest germs in milk — as we have noted — are those causing sourino- of milk ; they are invariably present and are about the only kind existing in very clean milk. They act to fer- ment or change the natural sugar of milk into an acid (lactic acid), and if they occur in large numbers a few hours after milking it is a sign that the milk has not been properly cooled and will sour early. Lactic acid germs, or those producing souring of milk, besides being the most common, are of most importance in their influence on milk and its products. They exist in very small numbers in milk soon after leaving the cow, but as they grow more readily than all other germs in milk at favorable temperatures (above 50^ and better over 70° F.), they often constitute almost 50 per cent, of all the germs in twenty-four hours. While, after this time, they gradually crowd out the different varieties of competing germs until they produce so much acid that the milk or cream sours and curdles, and they have multiplied so rapidly and have made the milk so unfavorable for other germs that they form from 90 to 99 per cent, of all the germs present. This is a most favorable occurrence, because the flavor of most butter and cheese is chiefly dependent on the action of the lactic acid germs, and in their growth they protect the milk from the action of miscellaneous germs which would spoil these products. Even to man the growth of the lactic acid germs is a favorable happening, as they are not harmful to adults in themselves and tend to check the development of other harmful ^erms in the digestive canal.* As we have pointed out, heating milk to 155° or 165^ F. readily kills the lactic acid crerms. Therefore such milk does not sour, but is changed by the action of other harmful germs so that it rots * Indeed Metchnikoflf, perhaps the most celebrated living authority on the action of germs on the body, beUves that lactic acid germs in buttermilk consti- tute one of the best agencies for prolonging life. 14 CLEAN MILK or putrefies when old. A low temperature (40^ F.) also retards the development of the lactic acid germs and they are killed when the milk or cream becomes very sour by means of the lactic acid they themselves produce. The action of these lactic acid orerms is taken advantage of in the ripening of cream for butter by adding them in great numbers, either by the use of sour cream or milk, or by laboratory methods by which they can be obtained in pure culture — that is, free from admixture with other varieties of germs (see page 39). Lactic acid germs are not found in milk when it leaves the udder, but enter the milk when it is exposed to air. They are thought to reside on the skin of the cow, in dust, in the air or surroundings of the barn. Ordinary market milk at 50^ F. sours in 120 hours; at 60*^ F. it sours in 66 hours; at 98^^ it sours in 16 to 18 hours. At the Paris exposition of 1900 there was an exhibit of dairy products, under care of Major Alford of the U. S. Department of Agriculture, which consisted of fresh milk and cream shipped from Illinois, New Jersey and New York in hot weather (July). Coming some 3,000 to 4,000 miles, the cream and milk were perfectly sweet a fortnight after being bottled, while the only other competitor was the French with a local supply which did not keep a day after reaching the grounds. Cleanliness and cold were the only methods used in so wonderfully preserving this milk, If milk is very dirty, however, it is not safe to keep it too long with ice, even if it does not sour and is unaltered in taste, as various sorts of harmful germs may develop at a low temperature. Thus, milk containing, soon after milk- ing, some 800,000 germs to the cubic centimeter, after four days at 41*^ F. contained almost five million germs and became sour. At the end of ten days this same milk con- GERMS IN RELATION TO MILK 1 5 tained over 400 million germs, or over ten times the num- ber of germs in the same milk kept the same time at 59^ F.* The milk kept at a higher temperature soured more quickly and the acid destroyed many of the germs in the process. There is a large class of germs known as putrefactive germs because they produce changes in milk which are akin to rottincy of meat. If these continue to develop long enouo-h they may impart a bad odor to milk or its products and are likely to induce diarrhoeal diseases in children. These germs are more liable to arise from the contamina- tion of milk with manure and are the germs which have escaped from the intestines of the cow. If milk contains many of this type of germs it signifies that the milk was withdrawn under filthy conditions. There are a oreat number of germs in milk which apparently have no effect upon its character and also are not harmful to the consumer. It is practically impossible to discover the germs of special diseases in milk with any certainty, so that besides recognizing the chief types of germs— the lactic acid germs, the putrefactive germs, and miscellaneous germs whose action is unknown to us — the best that can be done at present is to estimate the number of germs in milk per cubic centimeter. Large numbers of miscellaneous and putrefactive germs signify that the milk is contaminated with filth and is most dangerous. Large numbers of lactic acid germs indicate that the milk has not been kept cool enoucrh or is old. Freedom from any considerable number of germs is a pretty certain sign that the milk has been drawn from the cow and handled in a cleanly manner ; has been properly cooled and is likely to be uncontaminated *Swithinbank & Newman. 1 6 CLEAN MILK with disease-germs. This is the justification of cities which require that milk shall not contain more than a specified number of germs (bacteria) to the cubic centimeter. Thus the law in force in Boston requires that milk sold in that city shall not contain more than 500,000 germs to the cubic centimeter. It has generally been admitted that it is difificult to obtain any large supply of milk which shall certainly contain less than 30,000 germs to the cubic centimeter. In various parts of the United States milk of such purity is now sold and is often called " Certified Milk," when certified by some responsible body who have a laboratory to daily determine that the milk comes up to the required standard. The name "Certified Milk" originated with Henry L. Coit, M.D. He established a commission of medical men in Newark, N. J., in 1893, who made an agreement with a dairyman of Caldwell, N.J., to furnish milk subject to their requirements and inspection which should be known as "Certified Milk" when approved by the commission. Any person who pretends to produce clean milk must submit to the germ standard, as this is the best m.eans of estimating purity which we now possess. Exactly what that standard should be has, however, not been generally agreed upon.* It is perfectly possible to produce milk which shall not contain more than a few hundred, or, at most, not more than 2,000 to 4,000 germs to the cubic centimeter without great expense, if every precaution to secure cleanliness be observed in milkinof and handllno- the milk. The usual contamination of milk with germs may be judged by the following figures with the understanding that great improvement is taking place owing to the interest * It is not unusual to find 10,000 germs as the maximum number per cubic centimeter permitted in certain localities for certified milk. The standard of Albanj^ for certified milk has been 80,000 ; for Rochester and New York City, 30,000 ; for Philadelphia and Milwaukee, 10,000. GERMS IN RELATION TO MILK 17 which has been shown in the matter of obtaining a pure milk supply in recent years by physicians and others. In Boston, during the spring of 1 890, 5 7 samples of milk showed an average of 2,355,500 germs in the better class milk, and of 4,557,000 germs in grocery milk. In winter the growth of germs is considerably lessened by the colder temperature and this is somewhat counterbalanced by the filthier condi- tions of the barn floors, air and of the animals. On the whole, winter milk is, however, much freer from germs. The New York County Medical Society issue a certificate of inspection to farmers who will follow their directions for producing a second-grade, pure milk which shall not average over 100,000 germs from May to October, and not over 60,000 germs from October to May. In Seattle I found in twenty-eight examinations of different samples of milk on as many days in May and June, that sixteen samples averaged over 3,000,000 germs, and twelve samples less than 1,000,000 germs per cubic centimeter. The examina- tion of these milk samples was done when the milk was fifteen to thirty-six hours old, on the way to the consumer's house, being taken from the delivery wagons or on arrival of the milk train. A great many conditions may alter the number of germs in milk if milk is not produced and handled in a proper manner. Time and temperature are the two most important factors upon which the growth of germs depends — and the greatest of these is temperature. The milk from one farm examined at the same hour on two consecutive days averaged 1,150,000 germs on the first day — which was warm for May — and 48,000 germs the following day, which was cold and rainy. The great increase of germs when milk is kept at improper temperatures, we have already noticed, 1 8 CLEAN MILK the number of germs in such milk depending entirely upon its aofe. To show the effect of dust and unclean utensils on milk I may cite the following : a sample of pasteurized milk, taken from a delivery wagon and examined by the writer, contained seven million germs, while from the same wagon was also taken a sample of the same milk put into sealed milk bottles which contained but 24,000 germs to the cubic centimeter. The first sample was taken from a large can which was frequently opened to pour out small quantities for consumers and very likely the can was unclean before the milk was put into it. Germs do not multiply at all in milk at 32° F., no mat- ter how long it is kept. After the milk is withdrawn from the cow the number of germs in it generally diminishes for a longer or shorter time, and after this period the number rapidly increases. Thus at fifty degrees the number of germs may not be greater in thirty or forty hours than it was when the milk was first withdrawn. At a higher temperature the germs begin to multiply in the milk as soon as the third hour after it has left the cow. Each variety of germ has a special temperature at which it flourishes to best advantage. The lactic acid germs grow more favorably at comparatively high temperatures — from 70^ to 90*^ F., or even higher. There are certain special germs — not all of which have been studied — which produce special faults, or, as they have been called, diseases of milk. -Thus the butyric acid germs develop that acid by the splitting up the fat in rancid butter. Yellow, red, blue, brown and green milk are rarely seen and the particular coloration is due to changes produced in the milk by special germs. So also are slimy milk, bitter, stringy and soapy GERMS IN RELATION TO MILK 1 9 milk, entirely owing to germ-development and its effect on milk. This whole book is chiefly devoted to the influence of o-erms on milk, in one way or another, and further reference to the subject will be found under the special topics con- sidered. 2. Action of Germs in Milk Upon the Consumer. — As we have already intimated, germs do not enter milk during its formation in the udder of the cow, in normal conditions, but only gain entrance to milk through the medium of the air when the milk flows into the receptacle or cistern which communicates with the air through the opening in the teat. We showed that if the milk cistern was washed out clean and that if then a milking tube was introduced into the teat it was possible to secure milk free from germs altogether and which would therefore remain sweet indefinitely if kept in a sealed flask. If the cow is suffering from a germ disease it is possible for the germs to get into the milk, during its formation in the udder, from the blood of the animal, if it has a general dis- ease, or what is still more likely, if there is disease of the udder itself, the germs may find their way into the milk directly from the diseased parts. Inflammation of the udder may be caused by various germs, of which the germ of tuber- culosis is one and perhaps the most dangerous. This germ is found in milk then more frequently when tuberculosis affects the udder, but possibly also when tuberculosis attacks other parts of the cow. Just how common, and how important, therefore, is tuberculosis in the cow a source of the disease in man througrh drinking- milk of tuberculous cows, it is impossible to say. Cases of tuberculosis in 20 CLEAN MILK human beings have undoubtedly arisen from this source and in consequence it is essential that all cows should be tested with tuberculin, to exclude the possibility of tuberculosis, before the milk is used for dairy purposes. The germs of tuberculosis have been found not only in milk, but in cream and butter, although there is no cer- tain evidence that the disease was ever produced in man by the latter two products. The more ordinary germs which cause acute inflamma- tion of the udder, or garget, are those which produce acute inflammation and pus in all parts of the body, and pus or "matter" is often found in the milk (see page 159). Milk obtained from cows with garget is highly danger- ous to man and causes disease in him which in some cases resembles diphtheria and at other times has appeared iden- tical with scarlet fever. The milk from such cows may com- municate the inflammation of the udder to other cows in the same barn by means of germs carried by the milker's hands. Therefore cows with caked or inflamed udders should be kept apart and milked by one not milking the healthy cows. The milk from cows with foot-and-mouth disease has been the means of communicating this disease to man, giving rise in him to sore mouth, tender swellings under the jaw, an eruption of blisters or " cold sores " on the face, fever and disturbance of the digestion. Cow pox, milk fever, anthrax and pleuropneumonia in cows have been conveyed by the germs of these diseases, in their milk, to human beings. It may be positively affirmed that the milk from a sick cow or one receiving drugs, is not fit for human consump- tion. The milk of tuberculous cows may be safely fed to swine or calves after boiling for ten or more minutes. GERMS IN RELA TION TO MILK 2 1 The germs of typhoid fever, diphtheria and scarlet fever* ( rarely of cholera, dysentery and smallpox) occasion- ally find their way Into milk, owing to the milk coming in contact with human patients suffering from these diseases, or with their surroundings, or from contamination of milk utensils with water harboring the germs of typhoid fever. Also, by wading In filth containing the bowel and urinary discharges of human beings, cows may contaminate their udders with germs of typhoid fever and thus convey them to milk. Other agencies by which disease germs may be carried to milk and by which many cases of typhoid fever, dlph- terla and scarlet fever have been communicated to man are as follows : by attendants In the sick room coming in contact with milk, by dish cloths, brushes and other articles coming in contact with the sick and milk utensils as well, by contact of milk with flies and by contact of milk with persons handling human excrement. The lesson which should be taken to heart is that no sick person or one coming In contact with persons sick with communicable diseases, should be allowed to have anything to do with the handling of milk, milk utensils or be per- mitted entrance to. barn or dairy. Milk should be kept in a room separate from human habitation, and all the utensils should be kept and cared for in this milk room. Young chil- dren should be excluded from barn and dairy, as they are much more prone to contagious diseases than adults. Dogs and cats may be carriers of germs, dirt and parasites, and should also be kept out of these places. The water used In connection with the dairy should be examined for purity by a competent chemist. All forms of disease conveyed by germs in milk to * Physicians are required by law to report all cases of infectious disease to the local board of health. It should also be made mandatory that physicians state the name of the milk dealer supplying the patient with milk, in the case of every report of infectious disease, as is done in Mt. Vernon, N.Y. In this way endemics originating in milk contamination with human infections could be ireadily traced. 22 CLEAN MILK human adults are as nothing in comparison with the damage- wrought by germ-laden milk upon infants. Cholera infan- tum, in fact, is but another name for acute milk poison- ing. Practically almost all the cases of summer diar- rhoea in babies are caused by germs in milk. These are probably chiefly of the putrefactive type which enter milk from manure on the cow. Indeed, in some localities from 40 to 60 per cent, of the deaths in infants, from all causes result from dirty milk. The wonderful reduction in the death rate of infants in some of our laree- cities — which is one of the remarkable signs of modern progress — has been brought about solely by the recognition of this fact. This reduction is directly traceable to the use of pure milk or, where this is not obtainable, to milk heated to 165^ F. for thirty minutes, at which temperature the growth, of germs is killed or checked. Violent and often fatal poisoning, resembling cholera, is produced by a substance (tyrotoxicon) formed by certain germs in milk kept in dirty, covered vessels during hot weather. The same poison has some- times been found in cheese, cream and ice cream and has also caused fatal results. Heating impure milk will destroy this poison. Chiefly through the laudable and efhcient work of Health Officer G. W. Goler, M.D., in supplying cer- tified milk to the public of Rochester, N. Y., the infant mortality has been reduced as follows: 1887-1896, before milk work was done, the average mortality in infants under I year in the month of July was 1,010 ; 1897-1906, after the milk work was begun the average mortality was only 413 in July under the same circumstances. CHAPTER II. COMPOSITION OF MILK AND CREAM AND THEIR PRODUCTS MILK is a white, opaque fluid, when seen in bulk, but appears transparent in thin layers. It has a peculiar, pleasant odor and taste which cannot be described. They can best be appreciated — by comparison — when they are absent. Thus, milk which has been heated in open vessels or passed through a separator loses some of its finest flavor. This flavor resides in a volatile substance which escapes in either process. Chemically, milk is composed of all the essentials of a complete food. That is, it is a single substance which con- tains all the food-elements necessary to indefinitely support life. These food-elements are known technically as Pro- leids, Fat^ Sugar and Mineral Matters. Proteids in milk have the same food value as flesh or eggs. Water is, of course, the largest constituent of milk, forming about 87 per cent, of it. The solids make up the remainder of milk, amountino- to about 13 per cent, and comprising the substances we have just enumerated, proteids, fat, sugar and mineral mat- ters. Omitting the mineral matters or salts, we may, in a general way, remember the proportion of proteids, fat and sugar as four per cent, of each, the percentage of proteids being slightly b'elow and that of sugar slightly above these figures. The fat is the only one of these constituents which 33 24 CLEAN MILK varies greatly and this indeed varies tremendously (from 1.5 to 13. per cent.) and owing- to a great variety of circumstances which will be noted. If the fat is all removed from milk — which can practi- cally be done with the separator — we have left the skim milk, which is composed of the proteids, sugar and water. The sugar is of a kind peculiar to milk and therefore called milk sugar. It is found in no other substance and is not nearly so sweet as ordinary or cane sugar. The souring of milk is due to fermentaton of milk sugar which takes place through the action of certain germs (lactic acid germs), which we have already mentioned and which are always present in the cleanest milk. These germs lead to the breaking up (fermentation) of the sugar in milk into lactic acid (or milk acid). We have accounted for the sugar in the skim milk ; we have left for consideration the pro- teids and mineral matters. The proteids are of two kinds : Casein (or caseinogen) and Albumin. Casein forms nearly four-fifths of the proteids and is that part of milk which makes the curd of skim milk or the part of milk which forms the bulk of cheese. The word caseous means cheesy. The other kind of proteid or albumin remains mostly in the whey when milk is curdled. Casein exists in the form of microscopic solid particles floating in the milk, while the albumin is in actual solution, together with the mineral matter, in the water of the milk. This will be apparent if milk is kept a long while, when the cream (mostly fat) rises to the top ; ^he casein settles as another white layer to the bottom of the vessel, while in between these is seen a third clear layer (serum) consisting of water, in which remain dissolved the mineral matter and albumin (Fig. 2). ViQ. 2. The Constituent Elements of Milk-Fat, Serum, and Casein. (From Switliiubauk & Newman). COMPOSITION OF MILK AND CREAM 25 Milk curdles because the casein in it clots or coagulates by the action of dilute acid (the lactic acid of sour milk), or by the ferment, rennet, which represents the dried secretion scraped from the calves' stomachs. The second form of curdling is what naturally happens when milk is taken into the stomach as food. The albumin of milk is not curdled by the souring of milk or by rennet, but is, to a slight extent, by heat at a temperature over 162^ F. The fat in milk occurs as the most minute, microscopic globules which float through the milk and, on account of their buoyancy, rise more or less quickly to the surface and there form cream. These minute droplets of fat are appa- rently surrounded by a wonderfully thin pellicle or covering which is thought to consist of a layer of casein adhering by capillary attraction. If the fat were not thus surrounded the orlobules would run together and produce an oily mass. The fat globules vary greatly in size, some being six times the diameter of others. They average about 1-5,000 of an inch in diameter, and one drop of milk no larger than a pin- head may contain 1,500,000 fat globules. The larger glob- ules of fat are most buoyant and rise to the surface ; only t'.iG smallest remain in skim milk. The fat orlobules are larger In some breeds of animals, particularly the Jerseys, and the cream therefore rises more rapidly and completely. The fat globules are arranged in groups or clumps in milk instead, of being uniformly scattered throughout the fluid. This is of considerable practical Importance, for milk which has been separated or heated (pasteurized) does not cream so well because the clumps of fat globules are broken up and so do not rise so quickly or completely. For example, milk is passed through a separator not revolving fast enough to separate the milk from the cream (which is sometimes done to 26 CLEAN MILK remove the dirt from milk), and the milk is tottled. The cream will rise from this milk slowly and incompletely, and the cream, when it has risen, will appear so thin that a twenty per cent, cream may not seem thicker nor richer than rich milk. Pasteurizing milk will cause much the same result, if the milk is subjected to considerable agitation in the process. The mineral matter in milk comprises a very small amount of variety of salts and altogether they do not form quite one per cent, of the whole milk. The following table perhaps fairly represents the com- position of what might be called average milkf from a large herd of average cows of various breeds : Per Cent. Water 87.00 Fat 4.00 Proteids 3.30 Sugar 4.95 Mineral Matter 0.75 We will now consider in detail the various circum- stances which modify the composition of milk. It Is a curi- ous fact that the character of the food of cows has little Influence upon the composition of milk although it affects tremendously the yield of milk. The composition of the milk is dependent on the cow and breed, and is as much a characteristic as her color and as difficult to chanofe. The following table illustrates the average composition of the milk of herds of different breecis of cows : *Durham or Shorthorn Devon Ayrshire Holstein- Friesian Jersey Brown Swiss Common Native Fat Sugar Proteids . . . Min' Im't'rh 4.04 4 34 4.17 0.73 409 432 4.04 073 3-89 4.41 4 01 073 2 SB 4 33 3-99 0.74 5 22 484 3-.SS 0.73 4. CO 430 4 00 0.76 369 4-35 409 0.76 * Abstract of tables compiled hy Mr. Gordon, of Walker Gordon Laboratory. The figures for Holstein-Friesian in the case of fnt are rather low ; 3.2 per cent. fat would be nearer the minimum average. — K. W. f The U. S. Pure Food Act of 1906 fixes the standard formilk as follows: Solids not fat, 8.5 per cent.; milk fat, 3.5 per cent.; milk solids, total, 11.75 per •cent. Skimmed milk to contain 9.25 per cent, of total solids. COMPOSITION OF MILK AND CREAM 27 According to the statutes of the various states,* the required standard of composition of milk differs to a sHght extent, but as much as three per cent, of fat is demanded in every state, except Rhode Island, and solids amounting to twelve per cent., in most states, and as high as thirteen per cent, in some. The composition of milk varies according to the period of milking, the milk growing richer in fat and the fat glob- ules larger as milking advances, the last of the milking or "strippings" being very rich. Per Cent. Fat. t Fore Milk ; 38 Middle Milk 6 74 Strippings 8. 1 2 The reason for this is said to be that the fat globules are retarded by friction on the sides of the milk ducts in the udder and are forced out in abundance towards the last of milking. The percentage of the other solids remains prac- tically unchanged at different periods of milking. If cows are milked at frequent intervals the yield of milk is greater and the percentage of fat larger. The milk is formed in the cells of the udder and is conducted through numerous fine tubes of increasing size until it empties into a r,eservoir (holding about one-half pint on an average) con- nected with the upper end of the canal or opening in the centre of each teat. There are therefore four milk cisterns in the udder, one for each teat. It is probable that when the udder has become accustomed to hold in its ducts and cisterns a certain quantity of milk it will for a time secrete nearly the same amount during each interval between milk- * Laws in force in June, 1900. t Dr. Charles Harrington's analysis. 2 8 CLEAN MILK ings. After a while, however — if the cow is milked more frequently than usual — the udder will not continue to secrete the same amount of milk and the exceptional quantity obtained by frequent milkings will cease. Milking three times daily is practiced in some parts of Europe, but milk- ing more than twice in the twenty-four hours is rarely con- sidered economical in the United States, and is not done except in the case of very heavy milkers or in cows newly calved. The longrer the interval between milkinor the larcrer the quantity of milk and the poorer the quality of the milk ; the shorter the interval, the smaller and richer the yield of milk. In the summer the nights are short and therefore the morn- ing milking is apt to be richer. In winter the reverse is true and the night milking is likely to be the richer. The following analyses of the milk of one herd at the Delaware Experiment Station show this : July 24th February 5th. Night Milk. Per Cent. Fat. Morning Milk, Per Cent. Fat. 376 4.67 4-56 3-53 The season of the year influences the composition of milk. In the summer the percentage of fat and other solids is lowest. In the winter months the milk is richest in fat and solids not fat. Thus in the months of November, December and January, the solids may average 13.36 per cent, and the fat, 4.16 per cent.; while in May, June and July the solids may average 12.68 percent, and the fat 3.82 per cent. The changes in the composition of one cow's milk are great and may be brought about through various influences, as, for instance, fright, excitement, rough handling, change COMPOSITION OF MILK AND CREAM 29 of milker, exposure to bad weather, unfamiliar surround- ings, sudden change in the character of food, and irregu- larity in time of milking. It follows without sayino-that all these unfavorable influences are, as far as possible, to be avoided. In an analysis of hundreds of samples of milk from single cows, Farrington found that in the case of a Holstein there was as much difference between the highest and low- est percentage of fat as between 6.6 per cent, and 1.5 per cent., while in the case of the Jersey — in which sudden changes are most common — the highest was 12.3 per cent, of fat ; the lowest, 2.9 of fat. The mixed milk of a large herd is pretty constant in com- position except as influenced by the season and by the times the cows calve. For the composition of milk varies at dif- ferent times in the milking period. The milking period of the cow lasts about 323 days on the average after calving, she going dry about eight weeks before she calves again.* In cows which are well tended and fed the percentage of fat increases as the milking period progresses, so that the milk is richer at the close than at the beeinning- of the period of milking. The period of heat in a cow is often accompanied by a diminished yield of milk which is poor in fat (so that the fat may be reduced to one per cent.), and the milk curdles on boiling. The fat after this period is, however, propor- tionately increased over that usually present. The milk-yielding capacity of cows generally increases up to the eighth year of age, and then decreases. With the decrease of yield there appears to be often a decrease in fat and total solids in the milk. It was thought at one time The interval between two calving days averages about 398 days. 30 CLEAN MILK that the spaying of cows would prove of advantage in sus- taining the yield and improving the richness of their milk, but it has not been found so in practice, except in those ani- mals which are constantly in heat owing to disease. The dehorning of cattle is said to improve the yield of milk, but there can be no conceivable reason for this other than in the freedom from fighting and wounds which this practice accomplishes. The composition of milk is of great importance in that the value of milk depends upon the amount of fat it con- tains, other things being equal. It has now become the custom for creameries in most parts of the country to pay a sum for milk proportionate to the amount of butter-fat it contains as estimated by the use of the Babcock machine at certain stated intervals. First-class, pure or "certified" milks now sold for an advanced price in cities should contain a high average of fat. Such milk often averages five per cent. Then again it is for the farmer's advantage, if he is to produce a high quality of milk, that he know the composition of the milk of all his individual cows so that the poorer ones may be weeded out. This may be accomplished by the use of a. Babcock machine on the farm (see p. 142). Colostrtwi (common name beastings, etc.). — Colostrum is the milk secreted immediately after calving and differs very markedly in composition from ordinary milk. Colos- trum is of a slightly yellowish or brownish color and has a peculiar smell, a slimy consistency and salty taste. The proteids are at first large in amount and represent albumins rather than casein. For this reason the milk becomes curdled on boiling and this is a test for colostrum ; if it curds on boiling it is unfit for use. COMPOSITION OF MILK AND CREAM 3 1 The sugar In colostrum is not milk sugar, but repre- sents several other varieties. Th® percentage of fat is variable, while that of mineral matter is high. Colostrum usually separates into two layers on standing. Under the microscope there are to be seen in it very large globules of fat, called " colostrum corpuscles," and these are character- istic of this form of milk. The colostrum varies in com- position from one milking to another after calving, becoming more and more like ordinary milk. The following analysis will give an idea of its compo- sition : Per Cent. Water 78.7 Fat. 4.0 Proteids 14.$ Sugar 1.5 Mineral Matters i.o 1 00.0 While the proteids in colostrum are so soluble that they can be absorbed by the calf without any tax on its diges- tion, and appear to start up digestion in this animal, yet colostrum is not wholesome for man for from five to twenty days after calving. Legal requirements vary somewhat, but usually demand that cows' milk shall not be sold for fifteen days before, nor from five to twelve days after the calving of the cow supplying the milk. The boiling test, referred to above, will show when the milk is fit for human consumption. The milk is not fit for churning until five days after calving, nor from ten to twelve days for making cream cheese. Colostral milk and the milk obtained from the cow within fifteen days before calving have produced disease in man. Colostrum has caused high fever, inflamed throat and mouth, which were covered with small sores or ulcers; Z2 CLEAN MILK while milk from cows, withdrawn a few days before calving,, is sometimes the source of colic and diarrhoea in the human. The milk from a cow immediately after calving frequently contain's blood, coming from that which soils the udder and. tail after flowing out of the vagina. CHAPTER III MILK PRODUCTS IT is a curious fact that the quantity of cream obtained from setting rich or poor milk is about the same for rich as for poor milk, but the cream from the poor milk is much thinner and contains less fat. As seen in a glass quart milk-jar, the layer of cream forms almost a quarter of the bulk of the contents of the bottle, at first, but after twenty-four hours or longer the layer of cream becomes less, owing to the crowding together of fat globules. When cream rises in tall vessels it contains a great deal more fat in its upper than in its lower layers. In fact, of the cream which rises in a bottle of milk, the upper ounce contains as much sometimes as 25 per cent, of fat, while the fat in the cream regularly diminishes until at the lowest part of the layer of cream, which can be seen as a sharp line above the milk, the percentage of fat is not quite 10 per cent. As we have already said, the higher the creaming temperature the richer will be the cream, and for this reason the quantity of it will be much less than from the same amount of milk which is set at a low temperature. For the lower the cream temperature, especially at the end of the creaming period, the greater will be the amount of cream and the thinner will it be owinof to the sfi*eater quantity of water in it. Milk which has been watered throws up its cream much more rapidly than other milk.* * This accounts for the custom, with many farmers, of pouring a considerable amount of cold water into their milk cans when they wish to secure cream quickly for their own use. 33 34 CLEAN HULK Separator Q>vfi2iVt\ By the use of a separator, which consists of a rapidly whirling steel bowl (5,000 revolutions, more or less, per minute), the heavier portions of the milk — the skim milk and dirt — are thrown against the inside of the rotating bowl by centrifugal force, while the lighter portion — the cream — remains near the centre. The dirt sticks to the side of the bowl, where it forms a tough, sticky layer known as separ- ator slime. This separator slime is not composed by any means of filth entirely, because a good part of it is made up of the proteid constituents of the milk (curd); one authority says that nine-tenths of the dried slime is formed of this natural product of the milk. That there is a great amount of filth in ordinary market milk has been abundantly shown. It has been estimated that the citizens of New York eat daily ten tons of barn filth and refuse in their milk. This amount is probably exaggerated, since Berlin is said to furnish its inhabitants but 300 pounds of cow dung in its daily milk- supply, and, allowing a wide margin for our native progres- siveness, we could hardly be credited with beating the Germans so tremendously in this international filth contest. In the separator slime are to be found, in addition to the cheesy matter from milk, manure, fodder, hairs, particles of skin, insects, down from birds, threads from clothing, bits of bedding, cobwebs, bristles, soil, etc., and large quantities of germs. The slime forms from .04 to. 3 of i percent, of the weight of the new milk, depending upon its original state of cleanliness. The use of the separator is superior to all other methods of obtaining cream on account of its power to more rapidly and thoroughly extract fat from milk. Thus it shortens the period for growth of germs permitted by the MILK PRODUCTS 35 older methods of creaming, and — to some extent — removes germs already present in the milk. The cream, however, will be found to contain as many or more germs as the milk did before separation, although the skim milk leaving the separator may show one-third to one-half less germs in pretty clean milk, but in filthy milk the number of germs after separation is practically unaltered/'' Cream, after sep- aration, must therefore be rapidly cooled down from the high temperature of separation (86^^ F.) to 40° F. in order to prevent the growth of germs which have not been removed to any great degree by the process. The use of the separator to free milk of germs is not a success, although this method has been practiced in large cities to cleanse milk. None of the disease germs occasionally present in milk is certainly removed by separation. When used to cleanse milk the separator is run at a comparatively low speed so as not to separate the cream from the milk, but sufficient to remove much of the filth and therefore the so-called animal odor. Although there maybe an improvement in the flavor and odor of the milk, it will not keep any longer, showing that germs are not removed. Filtering milk by various devices has about the same value. The filth and dirt are removed more or less completely, and the taste and odor improved thereby, but the essential contamination — the germs — are not removed. For, as Prof. Conn has pointed out, the germs are so minute and so much smaller than the fat globules that it would be necessary to employ a filter which would remove all the fat in the milk in order to catch the grerms in the filter. "•■■ Recent experiments show thai of the germs present in whole milk before separation, 47 per cent, appear in slime, 29 per cent, in milk and 24 per cent, in creani after separation. — Eckles & Barnes, Iowa Sta. Bull., 1902. o 6 CLEAN MILK Complete separation of milk into cream and skim milk is sometimes done for cleansing purposes, the skim milk and cream being reunited. Many physicians believe that milk thus treated is often the cause of indigrestion in infants. Neither these nor any other methods will make dirty milk clean. Contamination of milk begins at the farm, and only at the farm can it be eradicated. Absolute cleanliness with respect to milking and everything which comes in contact with the milk, together with immediate cooling to 50"^ F. or below, will alone insure success. The importance of germs. in relation to milk is as great as to the operatmg surgeon, and the amazing progress in both surgery and dairying is due chiefly to the appreciation of this fact. Exclusive of fat, the percentage of the other constitu- ents of milk — proteids, sugar and mineral matters — is about the same in cream as in milk, unless the cream be of unusual richness. For the same reason, the composition of skim milk is about the same as whole milk, the fat excepted. The fat is practically absent from separator skim milk and is present in skim milk, from which the cream has been removed by hand, to the extent of one-half to one, or even one and one-half per cent. The following tables, illustrate these statements : Composition Composition Composition Composition of Milk of 2()^ Cream of 25^ Cream of 67^ Cream Per Cent. Per Cent. Per Cent. Per Cent. Fat 4.00 20.00 25.00 67.00 Sugar 4.50 48 4.8 22 Proteids 3.5 3.05 3.2 1.2 Mineral matters. 0.7 0.6 0.7 01 Composition of Composition of Hand-skimmed Milk Separator Skim Milk Per Cent. Per Cent. Per Cent. Fat 075 012 to 0.1 (hand) (power) MILK PRODUCTS 37 The cream from set-milk contains 90 to 99 per cent, of the germs which were present in the whole milk, because in rising the fat globules entangle the germs and carry them along to the surface. These germs are chiefly made up of the varieties which cause the souring of milk or cream (lactic acid bacilli), and these increase for forty-eight hours at favorable temperatures — 60'^ to 70^^ F. — in cream, and then gradually die out, owing to the unfavorable influence of the acid formed in sourinor so that in a week few remain. Duringf the first few hours there are to be found a orreat variety of germs in milk and cream, but the lactic acid bacilli crowd these out, because they grow so much more readily than do the other kinds of germs, and at the end of forty-eight hours there may be as many as 500,000,000 lactic acid germs to the quarter teaspoonful. Butter is com- monly made from cream which has " ripened." By ripening is meant the changes which occur in cream owing to the growth of germs in it during the process of souring. The ripening of cream may be compared to the change which takes place in grape juice when it turns to wine. Both changes — in the grape juice and cream — are brought about by fermentation, and fermentation is simply a term for describing the changes — chemical and physical — which occur in a substance owing- to the action of germs and their products upon it. In the ripening or fermentation of cream the germs alter the character of the cream and supply bodies which give to the butter its peculiar flavor and improve its keep- ing qualities. Butter made from fresh cream has less flavor and does not keep well. The sour milk germs give butter part of its flavor, but the miscellaneous germs which are crowded out by the former also are responsible for much of 38 CLEAN MILK the flavor. In this country the popular palate requires a much stronger flavored butter than the European taste, which regards our butter as rank in flavor. Therefore abroad it is often customary to pasteurize fresh cream to kill the miscellaneous trerms and add the sour milk eerms in the form of a " starter," thus orettinsf a butter made from ripened cream, but avoiding the stronger flavor caused by the miscellaneous germs. The flavor and aroma of butter, then, depend upon the varieties of germs in cream. Butter is thought to possess the finest flavor in May and June because at this season the greatest variety of germs flourish in the milk. The chief reason why butter is so much better from certain dairies than others is because the better dairies are the homes of special kinds of germs, which give butter a good flavor and aroma, while in the others — owing to want of cleanliness of the cows, barns, milk rooms, employees or utensils — special germs of filth which are unfavorable to good dairy products come to occupy the premises. The action of the germs is, then, the essential factor in the production of good butter, as in all other departments of dairying. As we have pointed out, the lactic acid germs, while in the minority in the milk just drawn from the cow, soon gain ascendancy by multiplying in milk or cream, and it is to this type of germ that the ripening of butter and of cheese is chiefly due. We have also shown that, to the miscellaneous germs in milk and cream, butter also owes some of its flavor. But as some of these are deleterious to flavor and aroma, and are not to be depended upon, the endeavor has been made to employ only the lactic acid bacilli to ripen cream. These are present in pure culture ; that is, they form the only type MILK PRODUCTS 39 of germ in the commercial starters, which may be bought in market in various shapes, as bottles of milk, pastes, pow- ders and pellets, all merely vehicles for the growth and preservation of lactic acid germs. This starter is added to fresh cream to ripen it. If the cream is already sour it is useless to add a starter. It is best to first heat cream to 155*^ F., to destroy the miscellaneous germs, before add- ing the starter containing the lactic acid germs, but in this country, where the added flavor caused by the miscellaneous germs is desired, the starter is more commonly added to fresh cream. The starters which were first used consisted simply of a quantity of sour milk or cream containing a great number of germs, suitable for ripening cream, which was added to fresh cream to quickly sour and ripen it, espe- cially in cold weather. These are called natural starters, and are still used extensively. To prepare such a starter the milk is withdrawn from the cow in the most cleanly manner ; the milk is then separated and the skim milk is collected in an absolutely clean vessel and set aside at a temperature of 60*^ to 70^ F. to sour. This sour milk may contain all sorts of germs, but if it is clean there are apt to be few miscellaneous germs and these are likely to be crowded out by the growth of the lactic acid germs, so that the result may be almost as pure a culture or collec- tion of lactic acid bacilli as is found in the commercial starters. We quote the following from Farrington : The foundation material for both kinds of starters is usually skim milk. This is first freed from most of its bacteria by heating it to 180 deg. F. or above, for at least one-half an hour. It is a good plan to keep this hot milk well stirred and covered while it is being heated. After this period of heating, the skim milk is cooled. The cooling is usually done by setting the can of hot skim milk into cold water. The quicker it is cooled the better. When the temperature of the skim milk reaches 80 deg. F., it is then in condition to 40 CLEAN MILK receive either tlie pure culture which has been bought from the dealer, or the sour milk which has been selected and allowed to sour naturally. The so-called commercial starters are made by adding to about a gallon of this skim milk a small quantity (about an ounce) of the pure culture which has been bought from a dealer in this material. After the pure culture has been added to the skim milk the mixture is kept at a temperature of about 80 deg. F, until the skim milk has become soured by the pure culture bacteria. This preparation is sometimes called " startolene," and it may amount to about four quarts of sour milk. This is added to a larger quantity of pasteurized skim milk, which has been prepared by heating and cooling as previously described, and the mixture is allowed to stand at a temperature near 80 deg. until it becomes sour and has an acidity of about six-tenths of one per cent.* If the cream in which the starter is to be used is now ready, the starter may be added to it in about the proportion often pounds of starter to one hundred pounds of cream. A small quantity of this starter is saved each day and added to a new lot of pasteurized skim milk. In this way the starter is carried on from day to day and a new lot for use in ripening cream is prepared every day. The natural starter is made in exactly the same way as the commercial starter, except that in place of the ounce of pure culture which is bought from a dealer, a small quantity of selected sour milk is added to the pasteurized skim milk. The starter is then built up from this mixture as before described. This in general is an outline of the methods used for making cream ripening starters. The successful handling of starters depends entirely on the carefulness with which the skim milk is pasteurized and the skill used in pro- tecting the starter from outside contamination by dust, dirty cans, etc. In some cases the butter maker often goes so far as to wash his hands before handling his starter. These refining precautions used to protect the pure cul- ture and the starter from contamination are very important. If the starter does not give satisfactory results, it is best to throw it awav and begin a new one ; but, when once obtained, a good starter should be propagated from day to day as long as possible, and the length of time which it may be kept pure depends on the care with which it is made from day to day. It is always better to seed a new lot of pasteurized skim milk with a por- tion of fresh starter taken out just before it is poured into the cream, than to attempt to propagate a new starter every day by means of buttermilk obtained from a churning of cream in which the starter was used. A buttermilk starter may often give good results ; but, as a rule, it cannot be depended on, because some unpleasant flavors may develop in the cream during its ripening. These, of course, are carried into the battermilk, and when this is used for making the next starter, the unpleasant flavors may be continued in the butter from day to day. * See page • MILK PRODUCTS 41 One of the important elements in starter making is the ability to detect a satisfactory starter when it is made. A person with a keen sense of smell and taste is able by inspection to select a good starter and know that it will })roduce good results, while other persons, without this ability, are unable to accurately judge between two different starters and they may keep on using a poor one day after day without noticing it. This faculty of judging starters may be cultivated by practice, and the butter maker who is most successful in training himself to detect a good starter, and a poor one as well, will be the most successful in making butter of a fancy grade. The commercial starters are more expensive, but uni- form, certain and convenient ; while the natural starter costs little or nothing and is less uniform but generally success- ful. Both are in common use. Butter made from ripened cream, besides having more flavor, aroma and better keeping qualities, is more readily churned and can be obtained in somewhat larger quantities than from fresh cream. Butter made from fresh cream is preferred by many persons and, perhaps it may be said, by those with the most refined taste. However, the market for such butter is limited and it must be sold imme- diately it is made. Fresh separated cream is much more readily churned than gravity cream. Cheese is made from the curd (casein or cheesy por- tion) of milk obtained by souring milk or by curdling it with rennet, chiefly by the latter method. The whey is removed in different ways. In soft cheese, as Brie or Cam- embert, the whey is merely permitted to drain naturally from the curd. The whey being not all removed, soft cheeses keep poorly. In the case of hard cheeses, the curd is cut up, and sometimes heated to i io° F. to toughen it, and pressed for days. Both soft and hard cheeses must ripen, which pro- cess takes days or months. The lactic acid germs are those chiefly instrumental in ripening hard cheeses, while 42 CLEAN MILK molds and miscellaneous germs ripen the soft cheeses. In ripening, the various flavors characteristic of the special cheese are developed through the action of chemical pro- ducts formed by the growth of these vegetable parasites or germs. In addition, the cheese becomes softened, and therefore easier of digestion throuofh the action of a ferment natural to milk, resemblinij rennet, the latter beincr a secre- tion of the animal stomach. How important is t]ie influence of special varieties of germs in the successful making of cheese may be appre- ciated from the fact that it is a practice to smear shelves and walls of new factories with fresh cheese (as Brie and Lim- burger) to convey to them the special germs necessary to produce the flavor and characteristics of the cheeses which it is desired to make. A starter is often added to milk from which American cheese is to be made. As in the case of cream for butter, the addition of the lactic acid germs tends to crowd out miscellaneous and undesirable orermsand give a more certainly uniform product. The commercial starters are most reliable for the ripening of cheese, as for butter. As a general practice, milk cannot be pasteurized to kill the undesirable germs before adding the starter, when cheese is to be made, because heating the milk destroys the ferment in it which assists in ripening cheese, and heated milk does not curd so well with rennet. Certain of the sour milk, and of the soft and hard cheeses are, however, made successfully from pasteurized milk or cream to which is added a starter. If cheeses made from unpasteurized milk, to which starters containing lactic acid germs have been added, are ripened in low-temperature cellars, the miscellaneous germs are not Hkely to develop. MILK PRODUCTS 43 The chemical composition of buttermilk and whey, bye products in the manufacture of butter and cheese, is given below. Buttermilk is usually sour from lactic acid, while the proteids are more digestible than in ordinary milk because existing in a flaky form.* Whey possesses but slight food value, containing only the ash, sugar and albumin of milk. It is sometimes the only food, when combined with a little cream, which infants with delicate digestion can tolerate. We also append a table showing the composition of butter. Buttermilk Whey Butter Percent. Per Cent, Per Cent, Proteids 4.06 0.81 i.oo Fat 0.93 0.36 84.00 Sugar aud Ash 4.40 5.71 3,00 Good cheese contains about -^t^ per cent, each of pro- teids and fat, and possesses two to three times the food value of meat, providing it is well digested, as It Is more apt to be if cooked with macaroni or vegetables. Skim Milk Skim milk forms a valuable food for man or beast, especially for calves and pigs. The milk should be fed young animals sweet, and warmed to the temperature of the body, when it possesses about one half the value of whole milk for food. The use of the hand separator at the farm will often be found lucrative, for the reason that the skim milk may then be obtained warm and fresh for calves or pigs and the cream bring as large a price as the whole milk, while retain- ing the most valuable element — the nitrogen in the proteids * Quite recently the advantages of concentrated and preserved buttermilk have been advocated. Its use will probably become much extended in time. Also an innovation is buttermilk made from clean skim milk. This should be set at 700-800 F. to clabber when it is churned and until the casein is in a finely divided state and immediatel)^ cooled to below 500 F. and sold within 24 hours. A pasteu- rized skim milk may be used. There is a great field for absolutely clean butter- milk thus made for consumption in cities. 44 CLEAN MILK of the milk — on the farm. This because the nitrogen is returned to the soil in manure. For man, skim milk, through its proteids, is said to be three times as cheap as meat, though a much more bulky food. If the skim milk is returned from the creamery for feeding, it is best that it be first pasteurized to kill any germs of tuberculosis which may be contained in it and to prevent souring. Calves should be permitted to suck the first three days of their existence, and then may be given whole and skimmed milk for ten days, gradually reducing the whole milk. After that time they may be given only skim milk, five to six quarts daily in three feedings for the first two weeks. At the end of this time five pints of skim milk may be fed twice daily with a tablespoonful of flaxseed or Indian meal to supply the defi- ciency of fat in the food. A liking for corn meal may be encouraged by placing a little on the tongue after feeding milk. Skim milk is fed pigs in the proportion of three pounds to one of corn meal ; to fowls, also, with grain. The utensils and troughs in which the skim milk is fed to young animals should be kept scrupulously clean, and the milk should not be fed sour. Bye-Products In speaking of milk products the bye-products of milk are used to an extent in the arts but little appreciated. This has recently been brought out in an address at Chicago by Dr. Nowak, the inventor of a process for using skim milk in the tannin qt- of leather. The curd or casein of skim milk is the essential part of the milk employed for the following manufactures : For sizinof straw and felt hats ; for making and Hazinor paper; for glazing and finishing leather; finishing and MILK PRODUCTS 45 sizing silk, cotton, woolen and linen goods ; for making wall paper, roofing paper and linoleum. Also, casein is an important ingredient of cements, glues, putty, woodfillers, paints (especially dry paints), imitation ivory for balls, and buttons, etc. Some of the most lasting of the old Roman structures were made from a mixture of milk, lime and sand, and the most celebrated old mural decorations of Europe from casein mixed with color. CHAPTER IV FEEDING FOR MILK IN feeding cows for milk the most essential fact to grasp is that the composition of milk can not be altered to any extent by feeding. The solids may be increased slightl)^ by a food very rich in protein, or, on the other hand, the solids may be lessened, if the diet is very watery, but the percent- age of fat, .-ugar and proteids in the milk is not affected to any degree by different kinds of foodstuffs. One often reads of the marked influence of a change of food in increas- ing, or otherwise, the percentage of fat in the milk. But, while a sudden change in the ration may produce a corre- sponding alteration in the percentage of fat in the milk, it will be found only a temporary matter. The single excep- tion to the rule that the composition of milk is not changed by feeding is when the animals are not in a normal condition. If an animal has not enough food to be maintained in a nor- mal condition, there may be a disturbance of the functions of the udder, as of any other function in the body, and therefore alteration in the composition of the milk. Milk is formed by the constant breaking down of the substance of the cells of the udder into the proteids, fat, and perhaps to some extent the sugar, of milk. This process is followed by a rapid rebuilding of the udder cells. The con- stituents of the food of cows are not transformed directly into milk, but are altered and absorbed into the blood and 46 FEEDING FOR MILK 47 serve only to build the cells of the udder, as they do any other part of the body. The quality of the milk from any cow depends upon the natural characteristics of the cells of the udder ; the quantity of milk depends on the capacity for rapid cell-building and, to a degree, upon the size of the udder. The cells of the udder being made of a sub- stance similar chemically to the proteids of the milk, there must be an abundance of protein in the food to constantly rebuild these cells as they liquefy into milk. Indeed, the proportion of protein in the food has to be higher in feeding for milk than for any other purpose. This proportion has been determined by experience and experiments (see Wolff's table below). While it is possible to secure the proper proportion of protein by the use of the greatest variety of fodders, the special foodstuffs which may be employed in any given case should be determined chiefly by the local cost of special fod- ders and the price of milk. The richer a food in protein the more costly is it, and, if the price of milk is low, it may not pay to increase the amount of proteids in the food sufficiently to attain to the maximum milk-yield. A food rich in protein tends to sus- tain the period of lactation and keep up the flow of milk — which is ordinarily greatest soon after calving — for a con- siderable period. In case of large milkers which receive an insufficient supply of protein, the proteids of the tissues of the body are called upon to make up for the loss of protein in the formation of milk from the udder cells, and the ani- mal rapidly loses flesh. Notwithstanding the fact that the composition of milk can not be materially altered by feeding under ordinary cir- cumstances, yet by good feeding and breeding (taking 48 CLEAN MILK advantage of increased fat yield in milk through careful selection), it has been found possible in several generations to produce an animal giving milk one per cent, richer than that common to its breed. This has been accomplished by some in the case of the Holsteins. Wolff's original feeding standard for milk cows, per day and i,ooo pounds live weight, is as follows : Pounds Digestible protein 2.5 " fat 0.4 " carbohydrates 12.5 Total dry matter 24. Nutritive ratio i to 5.4 The nutritive ratio means the proportion of nitrogen- ous to non-nitrogenous constituents of the food. The pro- tein represents the nitrogenous, and the fat and carbohy- drates together represent the non-nitrogenous nutrients, as the food constituents are called. But to put fat on the same basis as carbohydrates, in calculating the nutritive ratio, the percentage of digestible fat is multiplied by 2.5 and the result is added to the total of digestible carbohydrates. The reason for this is because fat is thought to have two and one-half times the food value of carbohydrates, since a given weight of fat produces two and one-half times as much heat in burning as carbohydrates. This method of reasoning is realized, however, to be very imperfect. In books* on cattle feeding tables showing the composition of foodstuffs may be found. The carbohydrates are found under the headings Crude Fibre and Nitrogen-Free Extract. There are other tables showing the percentage of digestibility of the fat, protein, crude fibre and nitrogen-free extract ^n the various fodders. *Armsby's "Manual of Cattle Feeding." FEEDING FOR MILK 49 By multiplying the amount of any of these constituents in any given fodder by the percentage of the constituent digestible, we get the quantity of the digestible constituent in the fodder. Thus, if we look at a table showingr the com- position of hay : Average hay we find contains in the 100 lbs. as follows : 9 lbs. protein, 2 lbs. fat, 43 lbs. nitrogen- free extract, and 26 lbs. crude fibre. To find the digesti- bility of these nutrients we look in another table and there discover that 46 per cent, of the fat in hay is digestible, 57 per cent, of the protein, and that the total amount of nitrogen- free extract in a coarse fodder represents the total quantity of digestible carbohydrates it contains. So in our 100 lbs. of hay we calculate that there are 5.13 lbs. of digestible pro- tein (multiply 9X-57)5 ^"^^ ^-Q^ lbs. of fat (multiply 2 X -46) and 43 lbs. of carbohydrates digestible. When we can not figure the amount of nitrogen-free extract as equal to the total digestible carbohydrates, as we do for convenience in a coarse fodder, we find the amounts of digestible crude fibre and nitrogen-free extract in the tables and add them together to represent the total digestible carbohydrate in the foodstuff. Fat is often spoken of as ether extract by some writers. It is not necessary, of course, to try to secure a ration which shall be the exact chemical counterpart of Wolff's table above, but only to approach it as nearly as may be, especially in the matter of protein. The general idea should be to take the foodstuffs at hand and look up the amounts of digestible nutrients* they con- tain and combine them in the proper proportions as indi- cated by Wolff's table. Proteinf is an expensive food con- *Armsby's " Manual of Cattle Feeding." t In cattle foods protein costs, by weight, twice as much as carbohydrates and about one-half as much as fat, but there is ordinarily enough fat in a ration. 50 CLEAN MILK stituent of nutrient, and it should be fed in the cheapest form of fodder available in the locality. The best manner of feeding is to weigh out the food necessary for the whole number of cows at one feeding and distribute the amount to each cow in proportion to her weight, secretion of milk, etc. Professor Haecker's work on cattle feeding teaches that the daily quantity of nutrients should be proportioned to the amount and richness of daily milk-yield as displayed in the followinor table :* FOR cows WEIGHING 1 ,000 POUNDS Milk-Yield Digestible Nutrients Required Daily Amount Testing in Fat Protein Carbohydrates Fat lbs. per cent. lbs. lbs. lbs. \^ 1. 10 8.81 24 lo w 1. 17 9.14 26 1.24 9-47 28 ^3 1.50 10.62 37 20 \\ 1.63 11.28 42 1.78 11.94 47 1.90 12.43 51 30 2.10 13-42 58 2.30 14.41 65 \^ 2 30 14.24 65 40 14 2..S7 15-56 74 (5 2.85 16.88 83 \^ 2.70 16.05 68 5c \\ 304 17 70 90 3-39 19-35 I 01 j^ 3.10 17.86 92 60 350 19.84 I 06 (5 3-92 2 r . 76 I 19 \^ 3-50 19 67 I 05 70 w 4.00 21.98 I 22 4.46 23.82 I 36 In practice it may also be broadly stated that there should be a certain proportion of coarse fodder, or rough- age, to the more concentrated foodstuffs, as grain and bye- products. Haecker's rule giving one pound of concentrated food for every three pounds of milk yield, affords a very useful basis for calculating- a ration. *This table and following rations were selected at random from Hoard's Dairyman. FEEDING FOR MILK 51 Thus, for a daily ration, 20 to 40 lbs, of roughage, including hay, silage, stover, etc., may be fed with about 8 lbs. of concentrates (consisting preferably of a mixture of a variety of grains) to a cow of average size and giving about 25 lbs. of milk daily. To cows giving daily 35 lbs. of milk, 10 lbs. of concentrates are suitable, and if the milk contains 5 per cent, of fat, 12 lbs. may be fed. The great milkers are often fed 30 to 40 lbs. of roughage with 15 to 16 lbs. of a grain mixture daily. Some such rations as the following may be used for milk cows of average weight and giving about 25 pounds of 4 per cent, milk : Roughage, 20 lbs, of timothy hay, with a mixture of oats, 2 lbs.; bran, 4 lbs.; and gluten, 4 lbs. This contains as follows : Dry matter, 26.3 lbs.; digestible nutrients — pro- tein, 2.18 lbs.; carbohydrates, J 3.09 lbs.; fat, 0.58 lbs. Roughage, 20 lbs. of timothy and clover hay, with a mixture of oats, 4 lbs.; barley, 3 Lbs.; and oil meal, i lb. This is equivalent to: Dry matter, 24.3 lbs.; digestible nutrients — protein, 1.88 lbs.; carbohydrates, 12. i lbs.; fat, 0.6 lbs. Roughage, 30 lbs. of ensilage and 10 lbs. of clover hay, with a mixture af barley, 4 lbs., and bran, 4 lbs. This ration is equivalent to: Dry matter, 25.5 lbs.; digestible nutrients — protein, 1..92 lbs.; carbohydrates, 11.92 lbs.; fat, 0.56 lbs. Roughage, ensilage, 30 lbs., and oat hay, 30 lbs.; with mixture of ground rye, 4 lbs., and gluten feed, 4 lbs. This feed is equivalent to : Dry matter, 23.56 lbs.; digestible nutrients — protein, 2.08 lbs.; carbohydrates, 13.32 lbs.; fat, o 54 lbs. It will be seen that the protein is a little low in all 52 CLEAN MILK these rations.* Cottonseed (or linseed) meal is one of the richest foodstuffs in protein we possess, and may be added to advantage to bring up the proportion of protein in the ration, as one pound of the meal is equivalent to about one-third pound of digestible protein. Not more than two to three pounds daily of cottonseed meal should be fed, however, on account of its poor digestibility in considerable amounts, and because in excess it may render milk unfit for use as an infant food. The following mixtures of concentrates may be em- ployed with an appropriate amount of roughage (if hay is. used, as much may be given as the cow will eat without waste) as daily rations for an average cow : Bran, 4 lbs.; corn chop, 3 lbs.; oil meal, i lb. Or, 2 parts bran ; 2 parts ground oats ; 2 parts gluten, and i part oil meal, giving 8 lbs. of the mixture daily. Or, 4 lbs. oats ; 3 lbs. bran ; i lb. oil meal. Or, 4 lbs. of bran and 4 lbs. of oats ; or, a mixture by weight of bran, 3 parts ; gluten feed, 2 parts ; corn chop, 2 parts ; and oil meal, i part, giving 8 to 10 lbs. daily. A ration having the proper proportion of nitrogenous to non-nitrogenous nutrients, or, in other words, the proper nutritive ratio according to Wolff, is now called a balanced ration. Oil meal is linseed meal. The exact amount of fat in the daily ration is not of much moment, but we should endeavor to approximate Wolff's feeding standard with the more recent modification (page 50) of adjusting the ration somewhat to the quantity and richness of the milk-yield. An amount of salt equal to one tea- spoonful should be given with the feed of each cow twice daily. * That is according to Wolff's standard of fifty years ago, but these rations, are calculated from the table to be found on page 50. FEEDING FOR MILK ^3 Cows may be watered to advantage twice daily; once before they are turned out for pasture or airing, in the mornino; and agfain before the evenine feeding. The matter of a pure water supply in the pasture, farm and dairy is of great significance. This is the case, not because the milk is contaminated by germs or poisons swal- lowed by the cow in impure water, but because the cow's udders become contaminated from wading in impure water. The dairy utensils may likewise be contaminated by wash- ing them in an infected water supply containing the germs of typhoid fever or dysentery. The presence of pools of water in pastures which in any way can be polluted with human excrement or urine should be Jxvoided. Germs or microorganisms existing in stagnant pools in pastures may impart a fishy taste to milk when such water is wallowed in or swallowed by cows. Water'" for cattle and for dairy pur- poses is best obtained from a public water supply of known jDurity, but when this is not possible a spring, away from sources of pollution, or a driven well, may afford excellent water. The neighborhood of a privy or manure pile should always be shunned, and surface drainage of any kind should be prevented from entering the well. Below the depth of of three and one-half feet germs do not live in the soil. Where there is any doubt — and some doubt must always exist concerning open wells and those situated near dwellings — a half gallon of the water should be submitted to a compe- tent chemist for analysis. Wells must be free of all solid objects, even stones, and water containing over 300 germs to the cubic centimeter is unfit for dairy purposes. The kind of food and manner of feeding cows has an * Cows do not like very cold water. Avoid giving it to them when 1' . si'.j c. 54 CLEAN MILK influence upon milk which is of much importance, especially when the milk is to be used by infants. Many chemical substances in the food are eliminated — either changed or unchanged — in the milk, and may impart to it an unnatural odor, taste or appearance, and may render It unfit for food. A sudden change from dry fodder to grass, or any other green food in considerable amount, is apt to give rise to milk which will cause digestive troubles in babies. Fresh corn fodder in considerable quantity, when fed to cows, will often render the milk harmful to infants. While roots and ensilage are commonly said to produce a milk which will disagree with infants, yet I believe these are harmless when fed in moderate quantities and after milking. Silage should not be given in a greater amount than twenty pounds daily, and not more than two pounds of oil meal should be fed, when the milk is especially intended for infants' use. The feeding of spoiled, moldy ensilage, and remnants of ensilage which have been allowed to accumu- late about the barn, are chiefly responsible for the harm this foodstuff inflicts upon milk. In fact, some authorities say that a ration of under 40 lbs. daily per cow is not damaging to milk. Some of the largest buyers of milk in the United States, however, refuse milk from ensilage- fed cows, and those versed in the use of milk for baby feeding find that a small feed of ensilage is safer. Grass, hay, clover and grains constitute the best food for cows supplying milk for use by babies. The time of feeding- is a matter of great moment. In general, it may be said that milk cows should only be fed after milking to avoid dust in the barn, and fodder, when given at this time — as mangolds, turnips, rutabagas, carrots FEEDING FOR MILK 55 or their tops — will not impart a bad odor or taste to the milk. It is not necessary to feed cows in order that they be quiet during milking ; they can soon be habituated to being fed after milkinor. Indeed, so orreat is the dang-er of dissemi- nating germs in the air when cows are fed before or during milking, that it is now recognized that when dry fodder is thus fed it is impossible to secure clean milk. Moreover, when hay is kept in mows open to the cow-barn, it is very difficult to produce clean milk. If feeding is done at milking time, it should only be moistened grain. There are certain pasture plants which are harmful to milk, and sometimes to human consumers of it. Amono- these are the following :. Poison ivy, poison oak, meadow saffron, Jamestown weed, sorrel, poisonous mushrooms, wild mustard, carrot tops, milkweed, sumach, henbane and skunk cabbage. The disease known as milk sickness, or trembles, which sometimes attacks man, and is exhibited by vomiting, great weakness and twitching of the muscles, is attributed to the drinking of milk from cows feeding on poison ivy. Meadow saffron consumed by cows may lead to severe diarrhoea in man drinking their milk. Milk is not of good quality for any purpose when the animals yielding it are fed upon swill, brewers' grains or food In a state of marked fermentation or putrefaction. Such milk may cause digestive disturbances in man — par- ticularly in babies— and the manure is very soft and stink- ing from cows eating fermented food, and splashes about, and is therefore more apt to soil the cow and milk. The milk produced with brewers' grain does not keep sweet so long as good milk should, neither are the cows consuming large quantities of it long-lived. The use of this food is now prohibited by law in most cities. Dried brewers' and 56 CLEAN MILK distillers' grains constitute wholesome food for cows. Moldy hay, straw or grain ; decayed leaves, salt hay, onions, garlic and cabbage may give to milk a bad odor or flavor. The expressed pulp from the sugar beet is inadvisable as a food for cows, because of its richness in potassium salts, which find their way into the milk and render it unfit food for human beincrs or animals. The milk of cows receivlnof drug^s is unsuitable for food, since many medicines are eliminated in the milk. Further- more, the milk of cows sick in any manner should be with- held from feeding purposes, as poisons in the blood or germs of disease may be conveyed to man or animals in the milk from the sick cow. The milk of cows underofoinsf the tuberculin test may be used as food unless the animal reacts to the test, when it should be permanently rejected for human consumption, or boiled before feeding it to animals. CHAPTER V HOUSING AND CARE OF COWS IN considering the practical, details concerned with the housing and care of cows, and the handling and mar- keting of milk, our object will be to emphasize the essentials required for the production of clean milk. Many different methods may be employed to attain the same end, but certain principles are essential. Ideal methods are unfortunately expensive, and the most approved appointments of the modern stable and dairy rival those of the surgeon's operating room in elaborateness and cost. Nevertheless, milk which will fulfil all the requirements necessary for " certification " can be produced by care and cleanliness in an ordinary stable, and without any great out- lay for plant. The Barn The essentials are that it shall be clean, light, airy, free from dust, flies and odors. In regard to the air space in a barn, this Is a matter which depend'^ wholly on the ventila- tion. When the ventilation Is good, 500 cubic feet of air per cow Is sufficient, as the air is In constant movement. The number of cubic feet of air, rather than air. space, is the Important matter. The King system for stables is that commonly used, the principle being to secure a current of air traveling at the rate of 200 to 500 cubic feet per minute through the barn. 57 58 CLEAN MILK The animal's heat is used to aid the movement of air. If the stable is too high, the animal-heat will be lost, so that in cold climates a height of 8 feet is sufficient, while a good width for a stable is 36 feet. The cows are to be placed in two rows running the length of the stable, and either facino" each other or toward the outside of the buildinof. There is much disagreement as to which arrangement is the better. If the cows face outward, there should be feeding alleys in front of them at least 6 feet wide, while the central aisle in the barn behind them is used for removing manure. If the cows face inward, the central aisle between the rows of cows is used for feeding purposes. In either case an overhead railway is often used for removing manure from the centre aisle, when the cattle face outward, or for carry- ing feed when the animals face toward each other. The writer gives the preference to the plan of facing the cows towards the outside of the building. By this arrangement the cows get more air and light, and their breath does not comminofle. At the same time the manure can be more readily removed, which is more important than ease of feeding, for the production of clean milk. In the cow stall, the chief object should be to have an arrangement which keeps the cows wholly apart and does not cumber the floor so as to make places where dirt can collect. The best floors are of concrete, covered with cement, and made some- what rough, so that the cattle will not slip. Some com- petent dairy men cover the cement with movable wood flooring, under the cows, to prevent them from lying on this hard and cold substance. (See Appendix.) If not of cement, the floor should be of planed, matched planking, and the cracks filled in with tar. In case planking is used, it is best at any rate to have the gutters of cement. HOUSING AND CARE OF COWS 59 To secure drainage of the floor of the stall, the rear half of it — that is, the half nearest the manure trench — should have a fall of two inches. The manure trench should be sixteen inches wide and about eight inches deep. The trench should have a fall for drainage, being, for instance, six inches deep at one end and ten inches deep at the other ; or, the whole floor of the stable may be made to slope, with the trench of the same depth from end to end. A number greater than forty cows is not desirable in one barn. There should be a continuous window space along each side of the barn. The windows may hinge from below, or be made to open and close as one, by means of a continuous rod. In cold climates, the sides of the barn mayi be built of two layers of inch, matched boards with a space of eight inches between, filled in with cut straw or sawdust. Besides this, building paper should be laid inside each layer of the boarding. The inner layer of boarding should be without beading and laid perpendicularly. The ceiling overhead should be perfectly tight. If it is composed of a double floor with building paper between, there is no reason why hay should not be kept overhead, providing it is brought down into a room separate from the main stable. There should be tightly-fitting double windows in winter in cold climates. The King ventilating system consists of numerous flues on all four sides of the building for the intake of air, 4x4 inches in diameter, and opening three or four feet below the ceiling outside the stable, and entering the stable just under the celling. These are furnished with sliding doors, or closed with an arrangement like a furnace register in a dwellln^f house. The outake for air should be only one for every twenty cows or less, being a shaft with 6o CLEAN MILK openings — the same size as the shaft — at the floor and just below the ceiling. This shaft should be placed on the out- side of the centre of one side of the barn, and should be carried straight upward like a chimney, six feet higher than the top of the roof. The shaft or flue should be absolutely air-tight, and may be made of metal, or preferably of two layers of wood, with filling of sawdust or building paper between, and covered with a cap, to keep the rain out, one foot above the top. The openings near the floor and at the ceiling should be pro- vided with doors or dampers of some kind. The number of flues and size of flues are governed by the number of cows in the barn. Only one flue is necessary for the out- take of air when there are less than thirty cows in the barn. I flue I ft. sq uare for 6 cows, I "1X2 (( " " 10 " I "2x2 (( <( " 20 " 2 " 2X2 fH sgppLif Tubular Cooler. The temperature of the milk may be lowered to a point two degrees above that of the water circulating through the cooler. HANDLING OF MILK AND CREAM 8i The Star cooler is made of two sheets of corrugated copper, tinned on its outer surface, which comes in contact with the milk. The water enters below, filling the entire space between the copper sheets, and flows upward through the cooler, while the warm milk drops through the holes punched along the whole length of the feed trough at the top of the cooler and flows down over both cooling sheets. As the milk is cooled, flowing down the outside, the water is warmed as it moves up the inside of the cooler (see Fig. 5). Fig. 7. Star Milk Cooler. The water supply for the cooler may be obtained in various ways : From a common source of water, as a town supply ; from a barrel or tank over the cooler (see Fig. 7) ; or from a barrel beneath the cooler by means of a siphon attachment (see Fig. 8). If it be desired to cool the milk much under 50*^, it may be necessary to use ice water in a part of the cooler. This is most economically accomplished by an ice water section, which is made to be hung on the bottom of the Star cooler and is practically a small counterpart of the 82 CLEAN MILK larger cooler above (Fig. 9). Ice water is run through the ice section alone and is obtained from an overhead barrel holding broken ice, over which water is sprayed from a large-surface nozzle, and flows from the barrel through a short hose throuQrh the ice water section. A similar result may be secured by using a tubular cooler (Fig. 6), arranged so the general water supply may be run through the upper half of the cooler, and the ice water or cold brine through the lower half. By either of Fig. 8 Star Milk Cooler these contrivances milk may be reduced to a temperature below 40*^. In place of the spray-head for sprinkling water on cracked ice in a barrel, to supply the ice water section of the Star cooler, it has been found (by my friend Mr. Paul- hamus, of Sumner, Wash.) that the following arrangement is better : A medium-sized cask is lined from top to bottom with a coil of a hundred feet or more of half-inch pipe. The water supply is connected with the bottom of the coil, and the top of the coil is connected with the ice water sec- tion of the Star cooler. Large pieces of cracked ice are HANDLING OF MILK AND CREAM 83 used to fill the cask to the top, to which may be added rock salt and then water. If salt is used, care must be taken to have the water running" constantly through the coil in the cask, otherwise the water will freeze in the coil. This way of cooling the water supply for the water section of the Star cooler is both more convenient and satisfactory be- cause the cask may be placed directly on the floor of the milk room, instead of up in the air as required for the sprinkler, and much less Ice is used than when a sprinkler is employed. Fig. 9. OOPYRIQHT, 1908, Star Milk Cooler. The advantages of such arrangements consist in utiliz- ing the natural temperature of the regular water supply of the dairy to do the chief part part of cooling the milk, while the ice water is only required to complete the smaller part of the reduction of temperature in hot weather. There are many different sizes of both the conical, tubular and Star coolers adapted to the quantity of milk which is handled. The tubular coolers are constructed to withstand high water pressure, while the Star coolers are not. While milk may be simply poured from the milking 84 CLEAN MILK pails through two or three thicknesses of cheese cloth into a receiving can, from which it is transferred to the receiving tank of the cooler, a better form of strainer is the trap variety (see Fig. lo), which is placed in the receiving tank of the cooler. The milk is poured into the upright funnel^ and has to rise from below up through the cheese cloth strainer to seek its level. Particles of dirt and foreign matter would naturally^ through gravity, fall to the bottom of the vessel and not be forced through WMth the milk, as commonly happens when milk is poured from above through a strainer. Fig. io Trap Milk Strainer. The simplest, cleanest and most inexpensive method of handling milk is to place it — as soon as milked — in a bottle- filler tank and run it at once into bottles and immerse the bottles in ice water. By this method, the need of a cooler is avoided and the chance of germs getting into the milk during its exposure to the air in running over the cooler. On the other hand, there are two objections. There should be four milkers or so to supply enough milk at any time, so that the mixed milk from a number of cows may be bottled. If one waits until milk from several cows is obtained, with one or two milkers, the germs will have a chance to multiply in the warm milk. The other objection consists in the HANDLING OF MILK AND CREAM 85 immediate bottling of milk without aeration. This objec- tion does not hold if the milk is withdrawn from clean cows in well ventilated stables, and milk is handled in this manner in many of the best dairies. The milk will be cooled to 45° F in ice water in an hour and by no method will the cream rise more rapidly. Hot Watei'. — Hot water may be readily obtained at comparatively small expense from a tank, such as is com- monly employed for supplying households with hot water when attached to the kitchen stove, by connecting the tank with a coil of pipe placed in an ordinary air-tight, wood stove. If a steam boiler is in use, the steam may be run into a tank of cold water.* In either case the stove or boiler should be placed in an adjoining room, to avoid dirt, while the tank is in the milk room. Cleaning Utensils. — After milking, all the utensils, in- cluding milk pails, receiving tank, cooler, straining cloths, etc., should be at once rinsed in cold water, then washed in hot water and soap powder or washing soda (sodium carbonate in 3 per cent, solution), and rinsed again in clean, cold water. Finally, all metal dairy utensils should have boiling water poured over them, which sterilizes and dries them at once. Dairy utensils should never be dried with towels. The cans should be scalded with boiling water or have live steam turned in them and be placed upside down on bars to drain in the milk room, thus also admitting air. Rusty cans should never be used ; they sometimes impart a fishy taste to milk. A fishy flavor is said to be given to milk and butter when washing powder is not well rinsed from dairy utensils, also by cows drinking stagnant water. The strainer cloths used over the milk pails and other utensils may be of various materials. The writer has em- * The steam heating tee is a most convenient appliance for heating water (see page 95). 86 CLEAN MILK ployed chiefly cheese cloth or rather gauze (which is cheese cloth prepared by washing, to remove the sizing and impur- ities, and dried), of the finest mesh, and two layers in thickness. A single thickness of coarse cotton flannel or Turkish towelling may be used, however. When the strainer cloth can not be sterilized in a regular sterilizer, it should be boiled for twenty minutes wrapped in a towel or clean cloth and left enclosed in this wrapping until used. Then it should be removed, but the fingers should not touch that part of the strainer cloth which will come in contact Fig. ir. COPYRIGHT, 1903, Wash Sink. "with the milk. Before sterilizing the cloth, it should be well rinsed in cold water, washed in hot water and washing soda, and rinsed in cold water again. Every little detail must be carried out conscientiously, as one failure in caring for the milk properly will spoil the result entirely. A convenient arrangement, when steam is employed, is the wash sink (see Fig. 1 1 ), provided with draining trays at each end. The can is placed upside down over the two nipples in the tray, one supplying a jet of water to rinse the can, and the other a jet of steam to sterilize or kill germs in it. Various forms of brushes are desirable for scrubbing HANDLING OF MILK AND CREAM 87 the utensils (see Fig. 12). They should be boiled daily for ten minutes after use. To keep milk cool in cans during shipment the refrig- erator car is commonly employed. Where this is not pos- sible, the writer has known of the use of a cylindrical, hollow can of tin, with open top and closed bottom, being suspended bottom down, well into the milk or cream, from the mouth of the shipping can, and filled with cracked ice. The milk can jacket, made of hair, felt and canvas, will protect cans against the effect of heat and cold to a considerable extent (see Fig. 13). Fig. 12. Various Forms of Brushes. Bottled Milk. — If milk is to be shipped in bottles instead of cans, the following utensils will be essential in the milk room : Glass Bottles, made to withstand heat, and Delivery Boxes. A Receiving Tank, with Trap Strainer. A Cooler, with Ice Water Section. A Collecting Tank. A Bottle Filler, with Table. A Sterilizer. A Washing Outfit. The cooling arrangement is precisely as described above for cooling milk to be shipped in cans. When there are eight or ten milkers, so that the milk from as many cows may be mixed as soon as milked without loss of valuable 88 CLEAN milk: time when it should be cooling, then the warm, mixed milk may properly be drawn directly into the bottles from the bottle filler. The bottles should, on being filled, be instantly immersed to the neck in ice water. In this way bottled milk may be suitably cooled, with the avoidance of the unnecessary exposure to two tanks and the air In passing over the cooler. The bottle filler is indispensable (see Fig. 14) for conveniently filling several bottles at once. By moving a lever one can fill from four to eighteen bottles to the same level at one time. The prices of these contri- FiG. 13. Milk Can Jacket. vances vary greatly with the size and material used in their construction. The sterilizer is an important utensil. It is a tight chamber into which steam is turned, with the object of destroying germs, and is made to hold the bottles and absolutely every other dairy utensil with which milk comes in contact. The germs are not only those which may have inhab- ited the milk, but occasionally there may be germs of dis- ease contaminating the returned bottle, owing to it having been in a house in which such disease existed. There are two styles of steam sterilizers — those in HANDLING OF MILK AND CREAM 89 which the steam is not under pressure, and those confining steam under pressure. The latter type is more efficient, in that with steam under pressure it is possible to obtain a much higher tem- perature than when it is not. Steam, when not under pres- sure, will not exceed in temperature boiling water (212° F.). With a pressure of ten pounds and a temperature of 241° F. Fig. 14 Star Side-Bar Filler. in the high pressure sterilizers, it is possible to destroy the germs in the milk utensils with as much certainty in twenty minutes as with steam at 212° F. in the low pressure ster- ilizers in an hour. The heavy pressure or high pressure sterilizers are, however, exceedingly expensive, and, if the bottles are properly washed, there Is practically no danger in relying upon the less expensive steam sterilizers In which the steam is not confined under pressure.* In Fig. 15 is * Indeed, washing and sterlizing may be done at the same time (see page 185). 90 CLEAN MILK shown a high pressure sterilizer. It must be built very strongly to withstand the pressure, which is over fifteen tons against the cloor alone, with a pressure of ten pounds of steam in the sterilizer. The matter of a sterilizer in Fig. 15. Star High Pressure Sterilizer. "which the steam is not confined under pressure Is a compar- atively simple affair. One may be home-made. The writer had a sterilizer "built of two-inch plank, lined with galvanized iron, with double doors fastened with an iron bar across the front. HANDLING OF MILK AND CREAM 91 The shape was nearly square and the capacity was about 250 quart bottles. There was a movable sheet of galvan- ized iron, partitioning the sterilizer in two, and movable shelves of the same, perforated with holes, in which the bottles rested upside down on their shoulders. The shelves stretched horizontally across the sterilizer, from each side to the partition in the centre, resting on galvanized angle irons soldered along both sides and on each side of the par- tition in the centre. The shelves were just far enough apart to give room for a tier of bottles. Shelves and partition were removed to allow of room for sterilizing the milk pails, cooler, bottle filler and strainer, cheese cloths, and tanks supplying and receiving milk from cooler, etc. The sterilizer was fed from a ten horse power boiler with steam from below, and also had an exit or exhaust in the bottom, while at the top there was a hole in which was a cork holding a thermometer in place, with bulb inside and recording part outside of steril- izer. The doors were not steam-tight, and no pressure of steam was attempted or possible in the sterilizer, but the temperature was raised to 212^ in about twenty minutes, and maintained for the time — one hour — occupied by steril- ization. A very successful sterilizer has recently been made by my friend, Hon. W. H. Paulhamus, of Sumner, Wash., entirely of concrete faced with cement, and costing about $75.00.* It is a rectangular chamber 6^ feet high by 8 feet wide and about 14 feet long and 6 inches thick, with one iron door. In the top, iron bars were used to reinforce the concrete. Two half-inch pipes enter one side of the chamber just above the floor for intake of steam from a twenty-five horse power boiler,and,at the top, there is a sino-le * See plate opposite page 184. 92 CLEAN MILK pipe for outlet of steam when sterilization is over to cool off the oven, and one to drain the floor. In the middle of one side there is also a pipe inserted, large enough to hold a thermo- meter. This sterilizer is enormous, and will hold loo dozen bottles and every bit of dairy apparatus used on four farms, including the milk pails and milk cans, coolers, and bottle filling apparatus, strainer cloth, etc. If one does not wish to make a sterilizer, the largest size only should be bought Fig. i6. Star Sterilizer. (Fig. 1 6), as it is most economical in saving the expense of doing several sterilizations daily, because with it all bottles and every article of dairy utensil can be sterilized at one time. In case the Star galvanized sterilizer is used, the bottle carriers described on page 102 may be employed to hold the bottles in the sterilizer, or a rack and truck similar to that pictured on page 103 and 104 may be utilized. This sterilizer is made of heavy galvanized iron, HANDLING OF MILK AND CREAM 93 riveted and soldered together, and holding from 240 to 632 quart bottles, according to the size. It is supplied with perforated steam coil and trapped drain outlet, and it is well to have an exhaust to carry off surplus steam, although the doors are not steam-tight when closed. A thermometer placed in the center of the door is also advisable. Both the heavy pressure and the galvanized iron sterilizers are made either with a door at one end or a door at each end. The latter arrangement is a convenience when there is a separ- ate room for washing the bottles, the sterilizer being placed in the partition between the washing and bottling room and the bottles passed in the sterilizer through a door in the wash room and taken out through the other door in the Fig. 17. Bottle Brush. Sterilizer in the bottling room. Every single utensil with which milk comes in contact, including the various tanks and strainer cloths, should be thoroughly washed and steril- ized after each milking for one hour at 212° F. To avoid sterilization twice daily, however, it is better to have two sets of utensils, which may be sterilized all together once daily. Washing Outfit. — A separate room should be provided for washing milk utensils where the best plan is pursued. Since we are considering the essentials for handling clean milk we have not included a wash room separate from the milk room, as clean milk can be handled in a combination bottling and wash room, although not to the best advantage. The bottles should be rinsed in warm water and washed with 94 CLEAN MILK washing soda and hot water (in 3 per cent, solution) with a bottle brush (see Fig, i 7), and then rinsed in clean hot water and Inverted over the trays or shelves, which are placed in the sterilizer. The most convenient arranorement is such as that shown In the cut (Fig. 18), two tanks, one holding lukewarm water in which the bottles are soaked and the other hot water containing washing soda, while at the end there are projecting nipples over which the bottles are inverted, and, by turning the lever, several bottles are rinsed at once. Each tank has an overflow standpipe to carry off the grease floating on the top of the water.* Fig. I Star Metal Wash Sink. An additional Improvement Is the turbine bottle washer shown in the illustration (Fig. 19). It consists of a revolv- ing brush which Is turned by a turbine wheel with steam at a pressure of twelve to fifteen pounds. In this cut are shown the two larore tanks on the left, for soaklnor and wash- Inof bottles in washlno- soda and water, and then the small tank, next the bottle washer, over which the bottles are inverted to be rinsed inside. This is accomplished by nipples as shown in the cut (Fig. 18) spraying water into the interior of a number of bottles at one time, which are * For a washing apparatus, where 1,000 or more bottles are handled, see Appendix, HANDLING OF MILK AND CREAM 95 then dipped in the small tank below to wash the outside of the bottle, and are transferred to the tank at the extreme riorht to drain. None of this special bottle-washing outfit is essential. Any convenient arrangement of tubs and hot water by which the bottles are put through three processes in wash- ine — first rinsine in warm water, then in hot alkali and water, and finally in clean hot water — will suffice. Fig. 20 Star Bottle Washing Outfit. If the bottles are thoroughly rinsed at the consumer's house the first rinsing in plain water may even be dispensed with, provided the bottles are thoroughly scrubbed inside with a brush and hot alkali water and well rinsed In clean hot water. The hot water may be supplied from a hot water tank, as suggested (p. 85), or by means Steam Heating ^f ^ steam heatinor tee (Fior. 20). Tee. , * . This is an arrangement by which water may be heated to almost any temperature desired (short 96 CLEAN MILK of boiling), by steam and cold water coming in contact, in varying proportions, according to the amount of either which is permitted to flow into the tee. Thus the steam enters the side and the water the top of the tee, both being regulated by valves in the steam and water pipes, and the hot water flows out below. Cold water or steam may be obtained separately also, from the device, which is com- paratively inexpensive. A very convenient bottle-washing machine is shown in the Appendix (p. 185.) The routine of operating the dairy would be as fol- lows : The empty, returned bottles would be taken from the wap-on boxes into the milk room and there rinsed in warm water, in one tub, and then scrubbed with a brush in another tub holding alkali and water,. as hot as the hand can bear.. Fig. 21. The bottles should be next rinsed in clean, hot water, in- verted in the racks and placed in the sterilizer, where they are sterilized at 212*^ F. (by a reliable thermometer) (Fig. 21) for an hour. The bottles should remain inverted until used. The milk is brought from the barn in milk pails or cans, as soon as milked, and poured into the Star trap strainer restino- in the receiving tank of the Star milk cooler with ice water section. The milk flows from the collecting tank of the cooler through sterilized cheese cloth into a large can, if it is desired to thoroughly mix the milk of many cows before it is bottled. Instead of a can for mixing the cooled milk, it is better to use the large tank for filling the bottles — that is, the bottle-filler tank ; and after twenty gal- lons or more of milk have flowed from the collecting-tank HANDLING OF MILK AND CREAM 97 of the cooler into the bottle-filler tank, the milk should be well stirred with a sterilized stirrer and the bottles filled while the milk is being mixed. The stirrer may be made like a huge fork, from heavy tin. The warm milk of several cows may be mixed in the barn by pouring the contents of a number of milk pails into a large can. But unless there are enough milkers to do this within a few minutes, it is better to carry each milk pail to the cooler, as soon as it is full and mix the milk after it Fig. 22 Machine for chopping ice used to pack about milk bottles. has cooled. The time elapsing between milking and bot- tling should be as short as possible. The milk must be cooled instantly after milking, and be bottled within an hour of milking. In some establishments the milk is bottled within eicrht minutes of milkine. The cooled, mixed milk is poured into the bottle filler and flows Immediately into the bottles, which are then quickly capped with sterilized, paper caps, and placed in the wagon boxes well surrounded with ice in warm weather. The milk should be delivered to the consumer the year round at a temperature not over 45*^ F. If not shipped immediately — as in case of the night's 98 CLEAN MILK milk — the milk may be stored in the wagon boxes over night with ice or kept in cold storage or in sufficiently cold water. (Fig. 22). All the dairy utensils should be rinsed in clean warm or cold water as soon as the milk has been bottled and then washed with scalding alkali water and rinsed with clean cold water, and sterilized an hour in the sterilizer, including the cheese cloth used in straining the milk in the milk pails, in the Star trap strainer, and that used over the can in which the cooled milk is mixed. The floor must be kept damp to avoid dust, and the windows and doors should be closed while the milk is being handled for the same reason. When dairy utensils are not in use, they may be kept in a sterilizer, Fig. 23. Banjo Conductor for carrying milk through a wall. or, if this is not practicable, it is well in many milk rooms to cover them with a clean sheet, to keep off the dust, and to rinse the cooler with clean, cold water just before using, for the same reason. A properly constructed and managed milk room should be dust-proof and dust-free, and such precautions should be entirely unnecessary. Turning live steam against the walls of the milk room each day is useful as an aid to cleanliness, provided that they are constructed to withstand the process. The employees in the milk room ought to tvear clean, washable clothes. Linen gowns, like those worn by butchers, which may be slipped over the clothes, are most convenient. The final test of perfection of cleanliness of the rrilk, produced as described, is the laboratory. Such tests should HANDLING OF MILK AND CREAM 99 be made once a week. If the milk is sold as "certified," it must receive the sanction of some reliable and disinterested society or person. The bacterial content or number of germs should not exceed 30,000* to the cubic centimeter, according to the consensus of authorities at the present time, in so-called certified milk. It is perfectly possible to produce milk which shall not exceed in number 2,000 to 4,000 germs to the cubic centimeter by the comparatively simple and inexpensive plant which has just been described above, as the author has practically demonstrated. Fig. 24. Cylinder for conveying milk through a floor. A more perfect arrangement in a dairy building for handling clean milk is of advantage when one can afford it. The most important improvement consists in separating the bottling or milk room proper from the wash room, in which the sterilization and washing of the milk utensils are done, and to devote two rooms to these different processes, (i) The boiler and engine should have a separate room, and, adjoining this, (2) a room for washing and sterilization, and then a room (3) in which the milk is cooled and bottled. * 10,000 germs is the maximum number permitted by many Milk Commis- sions. lOO CLEAN MILK A still further development comprises the following in the dairy building : A Milk Receiving Room. A Milk Room. A Bottle Room. A Wash Room. An Engine Room. A Boiler Room. A Cold Storage Room. A Shipping Room. A Lavatory. A Laundry. Fig. 25. Cream Cooler connected with Separator. The milk receiving room may be connected with the barn by a cable system by which two 5 to 10 gallon cans are suspended on can carriages running on an overhead wire. The milk receivinof room is on a hiorher level than the milk room, so that the milk flows from it through the floor through a funnel or cylinder, or through the wall by a Banjo conductor (see Figs. 23 and 24) directly into the receiving tanks of the cooler or separator in the milk room below, thus avoiding unnecessary handling. HANDLING OF MILK AND CREAM lOI The milk room should not be connected with tne outer air by a door or open window, but must be ventilated so as to exclude dust and only be connected with the other rooms. It contains the appliances for cooling and bottling milk we have already noticed, and also a separator, cream cooler and cream bottle filler (Figs. 25 and 26), if cream is to be made. The bottle room adjoins the milk room, in which the clean bottles are kept after being sterilized. One end of the sterilizer projects into this room from the wash room. Fig. 26. Cream Bottle Filler. The wash room contains the sterilizer, the bottle washing outfit, and a Babcock tester. The cold storage room is of great convenience where large quantities of milk are handled and may be arranged with natural ice, or by means of ammonia compression and an artificial refrigerating and ice-making plant. The lavatory and laundry are for the use of the employees in the dairy, the former with a shower bath, set basin and dressing room, and the latter to wash the clothes used by the employees. In the shipping room are the cases for holding the bottles, and the fioor platform for loading the wagons should be on a level with them. Where I02 CLEAN MILK there is machinery, as for a refrigerating plant, it is well to separate the boiler by a partition from the engine and fire room and thus avoid the dust, ashes and dirt from fuel.* Space does not permit of more than a brief outline of the more elaborate dairy plant, but we would refer to onef who makes a business of planning and installing such, from whom we have derived many valuable suggestions. The object of this book is to detail the less elaborate and more essential Fig. 27 COPYRIGHT, 1903, Bottle Carriers. methods which may be used by the farmer without great expense in the production of clean milk on a moderate scale. In the handling of milk bottles in the dairy, it is much more convenient — though not essential — if they can be transported and inverted in numbers without handling each bottle separately. Thus carriers have been invented for holding them, with reversing racks, so that the bottles may be inverted — as when they are sterilized— by turning over * For plan of milk house, see p. 179. t Samuel M. Heulings, Haddonfield, N. J. HANDLING OF MILK AND CREAM- 103 as many as 20 bottles at once (see Fig. 27V Cars are also made which are used to transport these carriers and the cars, carriers and bottles are all wheeled directly into the steri- lizer and out aeain without handling the individual bottles (see Figs, 28 and 29). Shipping Cases ancl Boxes. — Milk bottles of glass must be shipped in some sort of box. The writer has had such boxes made of strong galvanized iron (24 gage) with rolled edo-es at all the joints, with a hinged cover and padlock, and Fig. 28. COPYRrGHT, 1903, A Car for conveying carriers and bottles. with metal handles at either end. Padlocks must be made to have the same key fit them all ; but we have found great trouble in getting padlocks which were not continually o-ettino- out of order. For this reason, and because keys for such padlocks are readily obtained by outsiders, I recommend the use of a lead seal having an opening through which the ends of short wires are passed. The seal is then compressed by a special punch, thus locking the ends of the •wires and serving as a perfect padlock which is not likely I04 CLEAN MILK to be tampered with without detection. The seal and wire for each shipping box cost about one-sixth of a cent and may be obtained complete with the punch. One called "The Enterprize Punch & Seal" has proved efficient. The boxes hold 12 quart bottles, which are separated by a framework of galvanized iron on the same plan as the pasteboard partitions or fillers in ^^vith a normal NaOH prepared as described above. To do this proceed as follows : Place 10 c.c. of the HCl solution in an evaporating dish. Add 40 c.c. of distilled water and i c.c of phenolphthalein solution. Fill a burette (see Fig. 39) with some freshly prepared normal NaOH, and allow the NaOH to flow from the burette into the evaporating dish, drop by drop, until the faintest pink color appears in the acid solution and remains. This indicates the neutral point. Read from the burette the amount of NaOH which was required to neutralize the 10 c.c. of acid. If the HCl solution were exactly normal, 10 c.c. would require exactly 10 c c. of NaOH solution for neutralization. The solution prepared as above described (loo c.c. of HCl in 700 c c. of water) is usually too strong and requires more than lo c.c. of normal NaOH for neutralization. It nmst, there- fore, be diluted with water. The amount of water that must be added can be calculated as follows : Suppose there were required 11 c.c. of the NaOH to neu- tralize 10 c.c. of the HCl solution. This would indicate that the HCl was eleven- tenths of its proper strength. To make it normal there should be added to it one part of water to every ten parts of solution. The solution prepared now contains 790 c.c, and 790 X iV — 79 c.c. Hence 79 c.c. of distilled water should be added to the 790 c.c. of HCl to give a normal HCl solution. Add 79 c.c. of water and test again to correct any error. If the original HCl solution should prove to be too weak it is easier to make another solution a little stronger than to calcu- late the amount of acid necessary to bring the solution to a normal strength. The normal HCl solution once made will keep a long time without deteriora- tion if kept in a stoppered bottle. A one-tenth normal HCl solution may be made by diluting the normal solution with ten times its bulk of water at the time of using. 152 CLEAN MILK Fig. 43. J^ormal JfCl yhNormai AaO/f Instead, however, of adding to the mixture the one-tenth normal NaOH, add a normal solution, which is ten times as strong, and of which, therefore, only one-tenth as much should be added as would be required of the one-tenth normal. The whole of the medium is thus to be neutralized. It is well to test the accuracy of the neutralization by adding a few drops of phenolphtha- lein to a little of the neutralized me- dium. This should give the faint pinkish tinge ; if it does not, it means that the neutralization has not been properly effected. After neutralization, boil for five minutes and restore to the original weight, after which the reaction should be tested again and corrected if necessary. The material thus neutralized is too strongly alkaline for the proper growth of bacteria and must be ren- dered less alkaline by adding HCl. The amount to be added should be such as to bring the reaction to 1.5 per cent. acid. To produce this acidity add to the neutralized medium 15 c.c. of normal HCl for each liter. The acidity thus obtained is found to be that at which common milk bacteria grow most readily. After adding HCl in proportion Two burettes arranged for neutral- ^ izing culture media, of 15 c.c. to each liter of solution, pour into the mixture slowly the white of an egg mixed in a little water. Boil vigorously for a few minutes to coagulate the albumen, and then filter through absorbent cotton or through filter paper moistened with hot water. The material filters rather more easily through absorbent cotton, and if the directions above given are fol- lowed closely it will filter perfectly clear. After filtering the material is to be collected in a sterilized flask. MILK INSPECTION 153 Fill a considerable number of test tubes with the material from the flask, placing in each test tube about 10 c.c. of the medium, care- fully replace the cotton stoppers after the test tubes have been filled with the medium, and the whole quantity— both that in the test tubes and the flask — should be sterilized in a steam sterilizer for 20 minutes. To produce complete sterilization it is necessary to repeat the steaming on three successive days. The second and third sterilization require a longer time than the first, inasmuch as it requires some time to melt the agar, and, until the agar is thoroughly melted, the steril- ization is not effective. Upon the second and third days, therefore, the material should be steamed at least one-half hour. If an autoclave is at hand, sterilization at 120° C. for 20 minutes is sufficient. Fig. 44. Petri Dishes. Method of Making Quantitative Analysis of Milk. — In order to make an analysis of the bacteria in milk it is necessary to have an approximate idea of the number of bacteria which are to be expected. The reason for this is that the bacteria are commonly so numerous that it is necessary to dilute the milk highly with sterilized water in order that reliable results may be obtained. In the quantitative analysis of ordinary market milk it is commonly satisfactory to dilute the milk one hundred times with sterilized water, provided the medium to be used is the agar culture medium above described. If the milk is old and contains large numbers of bacteria, a much higher dilution than this is desirable (see p. 157), but for the kind of milk usually found in milk-distributing carts a dilution of one hundred times is usually satisfactory for the purpose here considered. 154 CLEAN MILK Several of the small flasks marked to hold 99 c.c. are filled to this mark with water and placed in an autoclave for sterilization. If it is desired to dilute the milk more than one hundred times there should, at the same time, be placed in the autoclave a number of the smaller vials filled with water to the 19 c.c. mark and others to the 5 c.c. mark (Fig. 42). All of these vessels of water are to be sterilized for an hour at a temperature of 120° (a steam pressure of ten pounds will do), after which they are to be removed. If an autoclave is not at hand the water may be sterilized by steaming for two hours. There is now taken from the milk to be tested a single cubic centimeter in one of the sterilized pipettes. Takhij of the sajjiple of milk is the most important point in the analysis and most liable to introduce errors. The number of bacteria found in different parts of a can of milk is by no means uniform, the surface layers containing different numbers from the deep layers of the milk. To avoid this irregularity it is necessary to give the milk a very thorough stirring or shaking immediately before the sample is taken, so as to distribute the bacteria as uniformly as possible. A cubic centimeter of milk is transferred by a sterilized pipette into one of the 100 c.c. flasks of sterilized water. The mixture is then to be very thoroughly shaken, so as to distribute the milk uniformly through the water. This thorough shaking is extremely important to break up the clumps of bacteria. Meantime six test-tubes of the agar culture medium have been melted by placing them in water over a gas flame. The tube should be kept in warm water at a temperature just sufficient to keep its con- tents from solidifying, A single cubic centimeter of the mixture of milk and water is removed with a second sterilized pipette and placed in each of the test-tubes of melted culture medium. The test-tubes are then to be gently but thoroughly shaken, so as to distribute the inoculated material uniformly. It is necessary to avoid shaking too vigorously, or otherwise bubbles will make their appearance, which will interfere with the accuracy of the test. The shaking should be thorough but not violent. Six sterilized petri dishes (Fig. 44) should have been placed upon a plate of glass which is held in as nearly a level position as possible MILK INSPECTION 155 and cooled artificially. This can be accomplished by taking a large, flat dish, filling it with water and ice then laying a large plate of glass' upon the top. The ice will rapidly cool the glass plate, and the petri dishes placed upon the plate will also rapidly become cooled. The contents of each of the test-tubes inoculated with the diluted milk are now to be poured each into a petri dish and the cover quickly replaced. The culture medium will distribute itself in a thin layer over the bot- tom of the petri dish and soon harden. The dishes are to be labelled and then set aside in a proper place for growth. If desired to hasten the analysis the dishes may be placed in a culture oven kept at a tem- perature of 98° F. For ordinary study of milk bacteria it is usually most satisfactory to leave the petri dishes at a room temperature of 70° F. , allowing them to remain for three or four days before the final study is made. The Study of the Plates. — The solidified culture medium fixes each bacterium at a single point. As the bacteria feed upon the cul- ture medium they grow and multiply, but, unable to move through the solidified medium, the descendants of each bacterium remain together in a mass and, in the course of two days, become abundant enough to produce a spot which can be seen with the naked eye. The plate, therefore, becomes dotted over with little points of various size and shapes known as bacteria colonies. It is only necessary, therefore, to count the number of colonies on one of these plates and we know approximately the number of bacteria that were present in one one- hundredth of a cubic centimeter of the original milk ; and multiplying the number by one hundred we get the number of bacteria per cubic centimeter of the milk. (See Plate T.) In counting these bacteria on the plate it is sometimes necessary to use various devices for dividing the plate into areas. If the number is small they can be counted without difiiculty, but if the number of colonies on the plate is large it is more convenient to place underneath the plate a piece of black paper with white lines ruled upon it, dividing the plate into a series of sections of equal size. Such cards for aiding the counting can be obtained from dealers in bacteriological material, and a quantity of them should be at hand in every laboratory to assist in the counting. If the numbers are not very great the counting may 156 CLEAN MILK be done without the aid of these slips, by simply marking the under side of the petri dislies with a waxed pencil, and thus dividing the plate into a series of sections which may be counted individually. The actual determination of the number of bacteria on these plates is not difficult, though it requires a little practice (see Plate T). The number thus obtained represents approximately the number of bacteria in a cubic centimeter of the original milk, but the number is only an approximate one. Different tests of the sample of milk will show considerable irregularities, and it is for this reason that six petri dishes have been made. Each of the six should be counted and the average result of the six regarded as the average number of bacteria per one one-hundredth cubic centimeter. But, apart from this irregu- larity in the samples, there are at least three other facts which make the analysis only approximate. First, if in the diluted milk there chance to be several bacteria clinging together, as is quite probable even after thorough shaking, these, when placed within petri dishes, would develop into a single colony and would be counted as one. This will naturally give a number in the analysis somewhat too low. A second and more serious difficulty is the fact that not all bacteria present in the milk will grow in the culture medium as above prepared. While a large proportion of the bacteria will develop on plates and make their appearance in analysis, there are some that do not grow at all, and, therefore, do not appear in the analysis. Third, it is impossible to pour out all of the contents of the tube into the petri dish, for some will inevitably stick to the tube. To obtain the absolute number of living bacteria present in a cubic centimeter of milk is quite impossible by any means at our command. The number obtained by the method described will always be an underestimate. But while it must always be recognized as approxi- mate, the results in different cases may be compared with each other. If two samples of milk show, one ten thousand and the other ten mil- lion, it is quite certain that these numbers express approximately the relative number of bacteria in two samples, though neither expresses the number accurately. rr.ATK T. Petri dish containing i cubic centimeter of a mixture of milk(i c.c.) diluted ■with 499 c.c, of sterilized water and mixed with sterilized agar culture medium. The white spots in the plate are colonies or collections of germs. Each colony is supposed to represent a single germ at the time the milk was examined. The dish rests on a glass plate lined in white with a black background to facilitate counting the colonies. When the colonies are small and numerous, only those in every other sector of the circle need be counted and the result multiplied by two. In the above plate there are only about 80 ])lainly visible, but with a common magnifying glass — and one is generally used for counting — about 125 colonies may be seen. In the dish photographed, 272 colonies were couuted, and, multiplied by 500 (the I c.c. of milk was diluted 500 times) gave 135,000, germs in i c.c. of milk. MILK INSPECTION 157 The following report,* describing the method of count- ing bacteria in Boston's milk supply, gives the most improved details of technique. The reporters are well recognized experts and have worked out some very ingeni- ous improvements which will be found of much practical value. The method decided upon after consideration of those employed in about 15 laboratories throughout this country was as follows : For media, one and one-half per cent, nutrient agar (B. C), 10 c.c. to a tube, reaction plus 0.7. The collection outfit was devised anew and consists of a case for carrying the samples made of copper with double walls interlaid with one-half inch felting. This case is divided into three compartments ; the central one for samples, the other two for ice. When iced and closed, a constant temperature of 34° F. is main- tained. The samples are carried in sterilized test tubes, the compart- ment holding eight racks of four tubes each. A smaller case was also made holding but three racks. These racks are made from copper tubing as suggested by one of us. (H. W. H.) Holes in the parti- tions of the case allow the ice water to circulate around the bottoms of the tubes. The use of the test tubes for carrying samples was sug- gested by S. C. Keith. For collecting, glass pipettes are used. These are carried in a detachable copper case, adapted for sterilizing, divided into two compartments, the upper for fresh sterile pipettes, the lower for the pipettes after use. For plating the samples, the agar, after being melted, is kept in a water bath between 40° and 45° C. until needed. In order to bring down the actual number of colonies in a plate to a countable figure, a standard dilution of i to 10,000 is used. For dilution water, square eight-ounce bottles, marked at 100 c.c, are used. This water is steril- ized in the autoclave under 15 pounds steam pressure for 20 minutes at a temperature of about 250° F. Two bottles are used for each sam- ple, giving a dilution of i to 10,000, with i c.c. of milk. Each dilu- * Herbert Winslow Hill, M.D., Director, and Francis Hervey Slack, M.D., 2d Asst. Bacteriologist, Boston Board of Health Bacteriological Laboratory. lu American Journal of Public Hygiene, November, 1904. 158 CLEAN MILK tion is shaken 25 times for tliorough mixing, as is also the sample. A sterile pipette marked to contain i c.c. and calibrated in the laboratory- is used at each stage, three being required for each sample. After expelling the milk into the first bottle, the pipette is rinsed to the i c.c. mark in the dilution water ; i c.c. from the first dilution bottle is transferred to the second dilution bottle ; then i c.c. from the second dilution bottle is transferred to the petri dish. The agar is then care- fully added, mixed with the diluted milk in the plate and allowed to harden. The plates are incubated in a saturated atmosphere at 37° C. (98.6° F.) for 24 hours. The colonies in a saturated atmosphere are not only more numerous, as shown by Whipple, than in a dry atmo- sphere, but also larger and therefore more easily counted ; 37° C. is used in preference to room temperature because the latter requires more time for satisfactory development of the colonies, and is also so variable as to give no standard for the comparison of results. The 24-hour incubation is used in preference to the 48-hour because, though the latter shows a slightly higher average count, the counts are not sufiiciently higher to materially change the report. One thousand consecutive plates incubated at 37° C. and counted at 24 and 48 hours gave the following results : 679 or 68 per cent, showed an increase in the number of colonies at the 48-hour count. In 195, or 19.5 per cent., the count remained the same ; 126 or 12.6 per cent, showed a decrease. 799 or 80 per cent, of these plates had counts below 100. The average 24-hour count on these plates was 15J2 ; the average 4S-hour count i8J4^. 193, or 19 per cent., had between 100 and 1,000 colonies averaging at the 24-hour count 275, and at the 48-hour count 283. Eight plates, about i per cent., had over 1,000 colonies each, averaging 1,287 ^^ the 24-hour and 1,334 at the 48-hour count. Only 13 plates changed their relation to the legal limit, nine going from below to above 500,000 and four decreasing. In many plates, the count is lower with the 48-hour incubation on account of small colonies becoming obscured in the growth of larger ones. There are also more spreaders. MILK INSPECTION 159 This annoying difficulty with spreaders, frequently met with even in the 24-hour plates, we now overcome by the use of earthenware petri covers suggested by one of us. (H. W. H.)* Spreading seems to be caused principally by water condensing on the petri covers and agar. The dry porous earthenware covers absorb this condensation water, still leaving the atmosphere saturated, as proven by the large size of the colonies. Organisms having an inher- ent tendency to spread from unusual motility are not prevented from spreading by this method. In Counting.— K box, a child's slate, a reading glass and a "lum- ber counter" are used. The box is 6x6x5 inches, with open bottom, glass front, and a four-inch circular opening in the top, painted black within and with- out, except the glass front. The slate has a circle cut in the surface, 4>^ inches in diameter, divided into 10 equal segments, the lines filled with red lead. The reading glass is a common four-inch lens magnifying about two diameters. The petri dish is placed over the circle on the slate and uncovered. The box fits over the circle, the reading glass over the box, thus pro- tecting the plate, keeping a constant focus and setting both hands of the operator free. A slight pressure of the thumb for each colony seen on the lum- ber counter accurately adds and records the count. As the dilution is I to 10,000, the actual count must be multiplied by 10,000 to obtain the number of bacteria in i c.c. of the milk. In addition to simply counting the bacteria it is essen- tial to examine for pus and streptococci which enter milk from an inflamed udder (garget) and may cause sore throat, dio-estive disorders, tonsilitis and what closely resembles scarlet fever and diphtheria in man (see p. 20). To dis- cover in milk the pus (or matter, such as comes from an abscess), and the germs which cause the Inflammation of the cow's udder, Dr. Slack writes me as follows : * Journal Medical Research, Nov., 1904. i6o CLEAN MILK " We centrifugalize the milk in small glass tubes (about 2 c.c. each, the ends being closed with rubber stoppers). Our apparatus carries 20 tubes and we centrifugalize for ten minutes at a speed of 2000-3000 revolutions a minute. " The sediment obtained on the rubber stopper is smeared evenly with a drop of sterile water over a space 4 sq. cm. By examining this sediment with a 1-12 oil immer- sion lens, we determine the presence of pus or streptococci and are also able to make a microscopic estimate of the num- ber of bacteria present." Since it is impossible to differentiate between dead leu- cocytes and pus, and since a certain number of leucocytes are normal (3 or 4 in a 1-12 immersion lens field) in milk, it is necessary to fix an arbitrary standard not to be ex- ceeded by these cells. The standard, observed by the Boston Board of Health, is 50 cells to the field of a 1-12 oil immersion lens (spreading the sediment from 2 c.c. of milk over a surface of 4 sq. cm,). If this number is exceeded the milk is condemned. After the milk is centrifuged in small glass tubes (see above), the sediment is placed on spaced, glass slides, dried with gentle heat and stained with methylene blue. During the course of the microscopic examination for pus, the number of bacteria can be deter- mined with a very fair degree of accuracy without plating the milk if the milk contains more than 100,000 bacteria in I c.c. Milk is condemned by the Boston Board of Health for streptococci when 3 tests are positive : i. When the centri- fuged sediment shows streptococci, cocci or diplococci. 2. When the plate from the same sample shows colonies resembling streptococci colonies, in excess of 100,000 to i c.c. 3. When such colonies transferred to broth and grown • MILK INSPECTION i6i for 24 hours at 2)1° C. show streptococci alone or in great excess of the other bacteria present. In an excellent article by Slack* the methods pursued by this Board of Health are described in detail, showing the system perfected by their own experience modified by the study of that pursued in 15 other prominent milk labora- tories in the bacterioloo;ical examination of milk. CIRCULARS. Jst. " Cettif ied Milfc/' Circular of Information Concerning the Requirements op THE MiL,K Commission of the Medical Society op the County op New York for ' ' Certified ' ' Milk. The Commission appointed by the Medical Society of the County of New York to aid in improving the milk supply of New York City invites the co-operation of the milk dealers and farmers in attaining that end. The sale of pure milk is of advantage to those furnishing it, as well as to those who use it. The Commission has undertaken to assist both consumer and producer by fixing a standard of cleanliness and quality to which it can certify, and by giving information concern- ing the measures needful for obtaining that degree of purity. The most practicable standard for the estimation of cleanliness \n the handling and care of milk is its relative freedom from bacteria. The Commission has tentatively fixed upon a maxium of 30,000 germs of all kinds per cubic centimeter of milk, which must not be exceeded in order to obtain the indorsement of the Commission. This standard must be attained solely by measures directed toward scrupulous clean- liness, proper cooling, and prompt delivery. The milk certified by the Commission must contain not less than four per cent, of butter fat, on the average, and have all other characteristics of pure, wholesome milk. In order that dealers v/ho incur the expense and take the precau- tions necessary to furnish a truly clean and wholesome milk may have some suitable means of bringing these facts before the public, the Com- mission offers them the right to use caps on their milk jars stamped with the words, " Certified by the Commission of the Medical Society * Journal of Infectious Diseases, Supplement No. 2, Feb. 1906, pp. 214-222. 1 62 CLEAN MILK of the County of New York." The dealers are given the right to use these certificates when their milk is obtained under the conditions required b>' the Commission and conforms to its standards. The required conditions are as follows : 1. The Barnyard. — The barnyard should be free from manure and well drained, so that it may not harbor stagnant water. The manure which collects each day should not be piled close to the barn, but should be taken several hundred feet away. If these rules are observed not only will the barnyard be free from objectionable smell, which is always an injury to the milk, but the number of flies in sum- mer will be considerably diminished. These flies in themselves are an element of danger, for they are fond of both filth and milk, and are liable to get into the milk after having soiled their bodies and legs in recently visited filth, thus carrying it into the milk. Flies also irritate cows, and by making them nervous reduce the amount of their milk. 2. The Stable. — In the stable the principles of cleanliness must be strictly observed. The room in which the cows are milked should have no storage loft above it ; where this is not feasible, the floor of the loft should be tight, to prevent the sifting of dust into the stable beneath. The stables should be well ventilated, lighted, and drained, and should have tight floors, preferably of cement. They should be whitewashed inside at least twice a year, and the air should always be fresh and without bad odor. A sufficient number of lanterns should be provided to enable the necessary work to be properly done during dark hours. There should be an adequate water supply and the neces- sary wash-basins, soap, and towels. The manure should be removed from the stalls twice daily, except when the cows are outside in the fields the entire time between the morning and afternoon milkings. The manure gutter must be kept in a sanitary condition, and all sweep- ing and cleaning must be finished at least twenty minutes before milk- ing, so that at that time the air may be free from dust. J. Water Supply. — The whole premises used for dairy purposes, as well as the barn, must have a supply of water absolutely free from any danger of pollution with animal matter, and sufficiently abundant for all purposes and easy of access. ^, The Cows. — The cows should be examined at least twice a year by a skilled veterinarian. Any animal suspected of being in bad health must be promptly removed from the herd and her milk rejected. Never add an animal to the herd until it has been tested with tubercu- lin and it is certain that it is free from disease. Do not allow the cows to be excited by hard driving, abuse, loud talking, or any unnecessary MILK INSPECTION i6 a disturbance. Do not allow any strongly flavored food, like garlic, which will affect the flavor of the milk, to be eaten by the cows. Groom the entire body of the cow daily. Before each milking wipe the udder with a clean damp cloth, and when necessary wash it with soap and clean water and wipe it dry with a clean towel. Never leave the udder wet, and be sure the water and towel used are clean. If the hair in the region of the udder is long and not easily kept clean, it should be clipped. The cows must not be allowed to lie down after being cleaned for milking until the milking is finished. A chain or rope must be stretched under the neck to prevent this. All milk from cows sixty days before and ten days after calving must be rejected. 5. The Milkers. — The milker should be personally clean. He should neither have nor come in contact with any contagious disease while employed in milking or handling milk. In case of any illness in the person or family of any employee in the dairy, such employee must absent himself from the dairy until a physician certifies that it is safe for him to return. Before milking, the hands should be thoroughly washed in warm water with soap and a nail brush and well dried with a clean towel. On no account should the hands be wet during the milking. The milking should be done regularly at the same hour morning and evening, and in a quiet, thorough manner. Light-colored wash- able outer garments should be worn during milking. They should be clean and dry, and when not in use for this purpose should be kept in a clean place protected from dust. Milking stools must be kept clean. Iron stools, painted white, are recommended. 6. Helpers Other Than Milkers. — All persons engaged in the stable and dairy should be reliable and intelligent. Children under twelve years should not be allowed in the stable durmg milking, since in their ignorance they may do harm, and from their liability to con- tagious diseases they are more apt than older persons to transmit them through the milk. J. Small Animals. — Cats and dogs must be excluded from the stables during the time of milking. 8. The Milk. — The first few streams from each teat should be discarded, in order to free the milk ducts from milk that has remained in them for some time and in which bacteria are sure to have multi- plied greatly. If in any milking a part of the milk is bloody or stringy or unnatural in appearance, the whole quantity of milk yielded by that 164 CLEAN MILK animal must be rejected. If any accident occurs by whicb tbe milk in a pail becomes dirty, do not try to remove the dirt by straining, but reject all the milk and cleanse the pail. The milk pails used should have an opening not exceeding eight inches in diameter. Remove the milk of each cow from the stable immediately after it is obtained to a clean room and strain it through a sterilized strainer. The rapid cooling of milk is a matter of great importance. The milk should be cooled to 45° within one hour. Aeration of pure milk beyond that obtained in milking is unnecessary. All dairy utensils, including bottles, must be thoroughly cleansed and sterilized. This can be done by first thoroughly rinsing in warm water, then washing with a brush and soap or other alkaline cleansing material and hot water, and thoroughly rinsing. After this cleansing, they should be sterilized with boiling water or steam and then kept , inverted in a place free from dust. g. The Dairy. — The room or rooms where the bottles, milk pails, strainers, and other utensils are cleaned and sterilized should be separ- ated somewhat from the house, or when this is impossible have at least a separate entrance, and be used only for dairy purposes, so as to les- sen the danger of transmitting through the milk contagious diseases which may occur in the home. Bottles, after filling, must be closed with sterilized discs, and capped so as to keep all dirt and dust from the inner surface of the neck and the mouth of the bottle. 10. Examination of the Milk and Dairy hispedion. — In order that the dealers and the Commission may be kept informed of the character of the milk, specimens taken at random from the day's sup- ply must be sent weekly to the Research Laboratory of the Health Department, where examinations will be made by experts for the Com- mission ; the Health Department having given the use of its labora- tories for this purpose. The Commission resen^es to itself the right to make inspections of certified farms at any time and to take specimens of milk for examina- tion. It also reserves the right to change its standards in any reason- able manner upon due notice being given to the dealers. After January i, 1902, the expenses incurred in making the regular milk examinations and inspections will be borne by the dealers. In fixing the charges each farm or group of farms will be considered a unit. The Secretary of the County Medical Society will send the bills to the dealers about the middle of each month. Prompt payment is requested. MILK INSPECTION 165 The monthly charges, which are intended to cover all expenses, will be as follows : For each group of farms sending daily less than 100 quarts $8.00 " " 100 to 200 " 10.00 " ** 200 to 500 " 12.00 ** " over 500 " 15-00 2d.— "Inspected Milk/' Circular of Information Concerning the Requirements op THE Milk Commission of the Medical Society of the County of New York for "Inspected" Milk. The Commission appointed by the Medical Society of the County of New York to aid in improving the milk supply of New York City has formulated the following requirements, affecting the farms inspected by it and the handling of the milk obtained at these farms. The Com- mission offers those dealers complying with these requirements the right to use caps on their milk bottles, stamped : " Inspected. Milk Commission Medical Society, County of New York." The requirements are as follows : 1. The Barnyard. (a) It must contain no manure in summer and none in contact with the stable in winter. (b) It must be well drained and kept reasonably clean. 2, The Stable s, (a) The ventilation and light must be sufficient for the number of cows stabled, so that the barn shall be light and the air never close. (b) The floor shall be wood or cement, (c) The ceiling shall be tight, if a loft above is used. (d) Basins, hand brushes, clean water, soap and clean towels shall be provided in the barn or adjacent dairy room. (e) The stable shall be whitewashed in the fall, and in the spring if necessary. (f) A sufficient number of lanterns shall be provided to allow the milking to be carried on properly. (g) Clean the ceiling and sidings once a month. (h) The bedding shall be shavings, sawdust, dried leaves, cut straw, or other material that meets the approval of the Commission. (i) The soiled bedding must be removed daily. 1 66 CLEAN MILK (j) The manure must be removed daily from the stalls and open manure-gutter. If a covered manure-gutter is used, it must be kept in a sanitary condition. (k) The application of land-plaster or lime on the floor daily is recommended. (1) Sweep the entire floor outside the stalls daily at least an hour before milking is begun. J. Water Supply. Pure water must be used for all purposes. It must be accessible and abundant. 4.. The Cows. (a) Discard milk containing mucus or blood and that from any diseased cow. (b) Reject milk from any animal forty-five days before and six days after calving. , (c) The food given must be suitable both in amount and kind and ' must not give a disagreeable flavor to the milk. (d) Keep the cows clean on flanks, belly, udder and tail. (e) Clip long hairs about udders and clip the tail sufficiently ta clear the ground. (f) The cows must be kept from lying down between the cleaning and milking. The best means of accomplishing this is by throat latches. (g) Clean the udder thoroughly before milking. 5. The Milkers. (a) No milker or assistant shall have any connection with the milk at any stage of its production if he has any communicable disease, or if he has been exposed to scarlet fever, diphtheria, typhoid fever, or small-pox. (b) After having everything prepared for milking, thoroughly wash the hands with soap, water, and brush, so that they may be clean when milking is begun. (c) The hands and teats must be kept dry during milking. If they become moistened with milk, they must be wiped dry with a clean towel. (d) Suitable clean outer garments, such as overalls and jumpers, must be put on before milking. 6. Utensils. (a) Strainers, whether metal, gauze, or cotton, must be absolutely clean when used for straining milk. (b) All dairy utensils must be absolutely clean and free from dust. MILK INSPECTION 167 THE MILK. 1. The milk must not be adulterated in anj- way. 2. It must average 3.6 per cent, of butterfat. 3. Cooling must begin at once. The temperature of the milk must be reduced to 50° F. within two hours and kept below that -tem- perature until delivered to the consumer. 4. When delivered to the consumer the milk must not average over 100,000 bacteria per cubic centimeter from May ist to September 30th, and not over 60,000 bacteria per cubic centimeter from October I St to April 30th. If the Commission's requirements are fulfilled, the bacteria will not be in excess of the number permitted. INSPECTIONS. 1 . The farms which furnish inspected milk must always be open to inspection by the Commission. 2. Samples of milk must be regularly submitted for bacteriologi- cal examination once a month. Fescr's Lactoscopc. This consists of a laro^e, hollow, orraduated orlass cylinder, into the centre of the base of which is inserted a smaller white glass cylinder marked with horizontal black lines. The test with the lactoscope depends upon the amount of dilution of milk required in order that the lines on the inner cylinder be seen when diluted milk is placed in the outer cylinder. The richer in fat, the more opaque is the specimen and the greater the dilution required. Thus 4 c.c. of milk are dropped from a pipette through the aperture in the top of the larger cylinder, and water is added in small amounts and thoroughly mixed with the milk by inverting the lactoscope with the finger over the top. When the milk is diluted sufficiently for the black lines on the inner white cylinder to be read, then the percentage of fat corresponds with the figures at the level 1 68 CLEAN MILK of the mixture on the larger graduated cylinder (in an upright position). As has been stated, the lactometer is unreliable when used alone, but, when employed in conjunction with the lactoscope, quite accurate results may be obtained. While milk which has been skimmed and watered may show a normal specific gravity by the lactometer reading, so milk which is exceptionally rich in fat may be only watered so as to still be within the legal requirements as shown by the lactoscope. By the use of both instruments, either skim- ming or watering, or both skimming and watering, may be detected — unless the milk is still of averag;e richness. Harrington (Practical Hygiene, p. 3) says : "A normal specific gravity with a low percentage of fat will indicate skimming and watering ; low specific gravity with normal or low fat, watering ; and high specific gravity and low fat, skimming. Low specific gravity with a high fat will indi- cate unusual richness ; thus cream has a very low specific gravity, due to its preponderance of fat. As a test of the accuracy of this process of examination, the author caused to be analyzed under his supervision 1,714 specimens, which appeared by those tests to be of good quality, and of this number but eight were found to have deviated materially from the statute requirement of 13 per cent, of total solids." In case inspection by lactoscope and lactometer showed a specimen of milk below the legal requirements, this result should be corroborated by the exact methods of the laboratory before it would be wise to institute legal pro- ceedings. APPENDIX. Dairy Cows THE writer has not said anything about the best kind of cow for producing clean milk, because it is as impossible to affirm posi- tively which is the best breed of dairy cows as it would be to state which is the best race of human beings. Each breed has its own valuable characteristics which are in accord or otherwise with the views of different cattle owners, depending on the experience, tempera- ment or characteristics of the owner. The dairy breeds of chief importance are four : The Jerseys, Guernseys, Holsteins and Ayrshires. The Brown Swiss and Short Horn are called dual purpose cows ; that is, useful for milk and beef. For dairy purposes alone they are inferior to the first four breeds men- tioned, however. The milk of the Jerseys and Guernseys is rich in fat, but moder- ate in amount (the Guernsey milk of especially deep yellow color) ; the Holsteins are large milkers, but the percentage of fat in their milk is low ; while the Ayrshires occupy an intermediate position — in respect to quantity and richness of their milk — as compared with the Jerseys and Holsteins. The milk of Jerseys and Guernseys is not quite so digestible for infants on account of its large fat globules. The milk is said to vary more in composition, in case of the pure bred Jerseys (on account of their excitable temperaments), and these animals are possibly more prone to tuberculosis. Clean Jersey or Guernsey milk is, however, infinitely preferable to the ordinary dirty market milk of any other breed of cows, and the writer has found that clean milk from grade Jersey cows (containing 5 per cent, fat) will agree perfectly with infants, providing that it is diluted properlv in accordance with its fat content, see p. 131. The average consumer 169 I I70 . CLEAN MILK of milk places much more importance on the richness of milk than any other quality. He can easily see and appreciate this quality, and the cleanliness of the milk he can not judge of — except to notice that it keeps well. Moreover, the average consumer buys the milk largely for the cream, which is commonly used for the breakfast cereal and coffee. For this reason a rich milk should bring the largest price, providing that it is clean. A Holstein or Ayrshire milk — or a clean milk obtained from cows of various breeds — may be sold for infants, and a 5 per cent. Jersey or Guernsey milk may be sold for general consumption at a little higher figure. If the whole milk is drunk by adults its richness is considered its most valuable quality. In Boston a milk containing 6 per cent, of fat — which may be obtained from some Jerseys and Guernseys — is sold for 16 cents a quart, and is especially intended for invalids. It is not unusual to separate the milk from different breeds on the farm and charge different prices for their milk. Milk intended for babies may appropriately contain about 4 per cent, of fat, and must be of special cleanliness and freshness. Rapid delivery of it is therefore necessary, which may require a special express rate on train and special wagon in the city. The bottles should be thoroughly pro- tected from dust by an outer cap of parchment, or tinfoil, over the ordinary paper cap. A milk for infants should constantly contain nearly the same quantity of fat, so as to give rise to a cream of uni- form composition. This is essential for the physician to calculate the fat in the different layers of cream (see p. 131), and such milk may be supplied if it is obtained from one breed of cows. For all these rea- sons the price of milk for infant feeding must be considerable — gener- ally 15 cents a quart retail. A five per cent, milk from Jerseys or Guernseys (not quite up to the certified standard for babies) may be sold for general household use for from 10 to 12 cents a quart. To give the reader an idea of representative cows of the dairy breeds we have included an account of a Guernsey, which heads the list of officially tested cows (taken from Hoard's Dairyman), and also tables showing the records of a trial — at the St. Louis Fair of 1905 — of Brown Swiss, Holsteins, Jerseys and Short Horns. The accom- !Pi w < i-r W o w ^ M w < W Ph bo o X .— ■ tn l-c O iH ■^ O ^ a c o cS I-' o o 2 I' a,y ^00 ^ PLANS OF BARNS AND MILK ROOMS l8l •which is higher than is generally permissible with the King system of ventilation to prevent loss of animal heat. The climate is, however, extremely mild, the temperature seldom dropping much below freezing in winter hereabouts. The King system is nevertheless followed ; there being ten inlets, between ten windows Fig. 46. I "'1 o o 8v JO ^\^ ■\ .■z v^ 8'— . C = \ \ 6 -4^ ^^/' ^ ^ S/z- UVVsWVWWVN- JO 35' Rough Sketch of Ground Plan of Barn for Forty Cows, W. H. Paulhamus, Esq., Sumner, Washington. (10) on each side of the barn, near the ceiling. These openings are six by six inches, and bring the air in shafts between the layers of the walls of the building from a point outside near the ground. The windows in the sides of the barn are three and one-half feet square, and between them in the sketch may be seen lines (No. 8) showing the point of entrance of the inlets for fresh air. The shafts for outlet of air are in the opposite corners of the lg2 CLEAN MILK building (7) and are two feet square with openings at the floor of the same dimensions. One special feature is the arrangement of the cement which covers the whole floor, except as noted. The entire floor slopes about one foot from one end of the building, so, while the gutters are the same depth, this permits of a flow for drainage. The cows face the outside of the building and the floor of their stalls is of two inch matched, planed Oregon pine, except for a strip of cement eight inches wide on the side of the gutter (6) on which the hind feet of the animal rest. All the rest of the floor back of the cows is of concrete with cement finish, while the side aisles in front of the cattle are of wood, like the floor of the stalls. The cows do not have the slippery, cold, cement floor to lie (or fall) upon, which Mr. Paulhamus believes an improve- ment over an entire cement floor. The stalls are shown in Plate IX. There are so many kinds of stalls that it is impossible to say which is the best, but these are simple, inexpensive and satisfactory, as soon as the cows get used to them. At one end of the barn are several rooms. One (i) is intended for keeping supplies, as baled hay, roots and grain in sacks, etc. One on the opposite side is a wash room with sink and hot and cold water (B), and a sheet iron stove (A) for wood with a coil of pipe inside to heat water (see p. 85). There is also a closet {d) for keeping the milking clothes. The next room (3) is a rather novel arrangement of the owner and assuredly deser\^es attention. This room has no connection with the inside of the barn, except by a tube for conveying milk at C. Here may be found a pair of steps which each milker ascends the moment he fills the pail. The milk is poured into a sterile tin funnel which carries it onto a Star cooler*, from which it falls, immediately cooled, into a can. The can, when full, is taken to the milk house (Fig. 47) some 200 feet away. The room (3) is reached from outside the barn and — with screened door and window, and smooth, clean, painted walls and ceiling, and * The milk flows from the funnel (which is in the open central aisle of the barn) through the wall, which separates it from room 3, and in that room falls on. the cooler. i-* ^ c o; 03 X ;s 01 o; 0) c j^ o V M a; C u, (ii w < 1» (% r-i »V PLANS OF BARNS AND MILK ROOMS \o cement floor — makes a good place for immediate cooling of the milk. The horizontal ceiling of the barn leaves much space in the roof, in which grain is stored. The grain is brought down in spouts to the bins at (2) and hay could be delivered from the loft above in the room(i) without causing any dust in the barn. The ceiling of the barn is absolutely dust tight with double floor and paper between. The barn is one hundred by thirty-five feet inside ; the centre Fig. 47. (6) O Wash Room h' I I ■ -<7— "'' 8 a-> a-. t>- c- d ■ e. VJWMWMA 1 \ Rough Sketch of Ground Plan of Milk House. W. H. Paulhamus, Esq., Sumner, Washington. aisle eight feet, and gutters eighteen inches wide. The side aisles are five and one-half feet wide. Box stalls for sick cows, or cows about to calve, are in another building. The buildings used for the milk rooms (Fig. 47) proper were altered for their present purpose and were situated farther from the barn than is necessary or desirable. A sketch of the ground plan of the milk house is shown in Fig. 47. The floors of the milk room and wash room are of concrete with 1 84 CLEAN MILK cement finish, boarded inside with planed, matched boards (walls and ceiling), painted white and ventilated after the King sj-stem. The space between the inner and outer layer of the walls is stuffed with sawdust and the rooms are very high-studded (fourteen feet). The sterilizer (8) is wholly of concrete, which is described on p. gi, and, if the buildings had not been already built before they were put to their present use, it is probable that the most convenient place for the sterilizer would have been in the wall between the wash and milk rooms, as in Mr. Farrell's (Plates VII, VIII). The sterilizer is supplied with steam from the 20-horse power boiler (6) in the wash room. This sterilizer is an original feature introduced by Mr. Paulhamus and works beautifully. It is of enormous size (see p. 91 and Plate XI) and very inexpensive, costing some $80. In cold climates it would have to be inside the building as suggested above. Another novel feature is the washing machine shown as (No. 12) in the sketch in the wash room. This was patented after its introduction at Mr. Paulhamus's farm and now sold by The Chas. H. Lilly Co., of Seattle. The machine con- sists of four tanks, a, b, and c, d and e. In a, is held warm water, in b and c, is contained alkali and warm water, and in d, is plain warm water. The three lines {g^ running lengthwise in the sketch, through the middle of the machine, represent three pipes running over the top of the tanks. These pipes are perforated with holes which are placed so as to correspond with the opening in each milk bottle when the bottles are inverted on wooden trays. Each wooden tray is made of slats which, in crossing, leave holes fitting the neck of an inverted milk bottle. The trays holds twenty-four bottles in three rows, so that when the tray is slid in place on top of the machine, each row of bot- tles is over one of the three pipes in the centre of the machine, and each bottle is inverted over* one of the perforations in the pipes. On one side of the machine are three rotary pumps (/) worked by the engine at (7). These continually pump water from the tanks into the the pipes, from which it is forced out in jets into the interior of each inverted milk bottle. The water then runs out of the bottles back into the tank over which the bottles are resting. The pipe shown on either side of the top of the machine at (Ji) is perforated with holes from which water is thrown over and cleans the outside of the bottles as they are pushed through the machine. Plate xr. This photograph shows the interior of the large all-concrete and cement sterilizer at the Panlhamus farm. The door is of iron. All the dairy utensils which come in contact with milk in any way are put in this chamber and kept at Sia** F for one hour daily. For description, see p. 91 , PLANS OF DARNS AND MILK ROOMS 185 The method of working is as follows : A tray holding twenty- four inverted bottles is placed on the top of the machine over the tank {a). The warm water in the central pipes is pumped up through the holes in the pipes into each bottle, thus rinsing it out. Another tray being pushed into the machine shoves the first tray over tank {b). Here the interior of the bottles is sprayed with lye and water. The introduction of another traj^ moves the first tray over the tank (<:). The tank {c) is really one with {h), the bottles here merely draining back into the tank again, no water being pumped into them. Another tray being placed in the machine pushes the first tray to {d). Here the bottles are rinsed with plain warm water to remove the Ij'e, and, at (.f), boiling water is injected instead of water to sterilize (for one minute) the bottles. About i , 500 bottles may be washed in one hour by this labor-saving device. The bottles must, however, be washed by hand if they contain old milk and have not been previously rinsed by the milk consumer. Also, one minute sterilization -•' is not sujB&cient and they must go for one hour's sterilization in the large sterilizer, when certified milk is desired. The water is heated by steam from the boiler (6) which runs the engine. A metal hood covers the whole top of the washing machine to prevent the escape of the water which is thrown from the pipes on each side over the exterior of the bottles. The machine with pumps costs about $200, and is sixteen feet long and twentj'-six inches wide (see Plate X). The platform (13) and floor of the milk-receiving room are some fifty inches from the ground. In the milk-receiving room at (9) is a raised platform three feet from the floor on which are scales holding a large milk-receiving tank in which is a Star trap strainer. After the milk is weighed it is run from a faucet into a funnel, conducting the milk through the wall, into a tank (10) holding some one hundred gallons, and from thence is drawn off into the Star bottle filling tank (11). The milk is cooled, as described, at the barn (p. 182), and the water supplying the Star cooler is cooled in summer by running it through a coil of pipe in a cask of ice water (see p. 82). * It is perfectly possible to sterilize milk bottles absolutely, if boiling water is pumped into the bottles for a longer time, as shown Dy bacteriological examina- tions of bottles washed by similar machines. The exhaust steam from the engine may be used to heat water to boiling point. 1 86 CLEAN MILK A sketch of the cow stall used by Mr. Paulhamus is shown in Pig. 48. The floor has been described (p. 182) as consisting of cement for eight inches in front of the gutter and (forward of this point) of two inches kiln-dried, planed, tongued and grooved Oregon pine. The dimensions are marked in the sketch, but the length of the stalls vary Fig. 48. ^/i-S Side and Rear View of Stall in Cow Stable of W. H. Paulhamus, Esq., Sumner, Washington. from four and one-half feet to five feet long, from the gutter to the manger, to accommodate cows (Jerseys) of different sizes. The floor of the stall slopes some three inches from front to rear. The stalls begin four and one-half feet long at one end of the stable and gradually lengthen till they are five feet long at the other end. Each side of stall is really a gate opening toward the right, to give more room to the milker and groomer, when open. They could of course be hung om hinges so as to swing in either direction. Plate; XII.— The improved "Drown" Stall. View shows cement mangers and floors fitted with iron stalls having two-way- movable partitions, The Drown vStall is one of the best made and is an improvement over either stall shown in that the side gates give more room to the attendant and open in either direction sideways and also upward. The raised feeding trench and hay rack are good features. The stall is patented and sold by M. L. Drown, of Madison, Wis. It is in use by some of the agricultural experiment stations and leading dairy farmers of this country. PASTEURIZED MILK 187 The gates are fastened with a wooden sliding bolt (not shown). The bottom of the rear posts may (for the lower eighteen inches) consist of galvanized iron pipe set below in the cement and above in the wooden scantling, for the sake of cleanliness. At the rear of the stall is seen a chain which is attached to rings in the post, on either side of the stall, by means of snap hooks. The manger has two com- partments, the lower for grain, and the upper or forward being for hay — with a sliding rack between the two which may be removed or lifted a little to clean out the floor of the manger. (Sometimes the whole manger, arranged with sides reaching to the floor of the stable, is made movable so that it may be adjusted to the length of the cow and locked by pegs fitting in the side posts.) The cross-piece at (C) is necessary to keep the cows from pressing forward and climbing over the manger. It must be adjusted somewhat to the height of the cow. This stall is convenient and inexpensive as compared to the iron stalls (Plates V and VI). There is nothing on the floor of the stable to col- lect dirt, as the manger does not touch the floor, but is eight inches above it. Pasteurized Milk. Milk is now thought to be truly a living fluid for some time after leaving the cow — unless it is killed by pasteurization. Pasteurized or dead milk is known to be less digestible and nutritious than clean, raw milk. The basis of this statement is as follows •. Babies fed con- tinuously on pasteurized milk are very apt to develop anemia, mal- nutrition, scurvy or rickets — the latter serious disorders dependent upon improper nutrition. Obstinate constipation is likewise generally seen in infants reared upon pasteurized milk. The same conditions are observed in calves which are fed exclusively upon pasteurized milk. They fail to gain properly in weight and suffer from under-development. Heating milk coagulates to some extent its albumin, renders the milk less coaguable by rennet in the stomach, and destroys the enzymes or ferments of milk. All these results account for its lessened digesti- bility. It has been shown that the poisonous waste-products, developed in the growth of germs in dirty milk, are not destroyed by pasteuriza- tion. As, for example, the special poisons arising from those types of 1 88 CLEAN MILK germs (colon bacilli) convej^ed to milk in cow manure. Moreover, while the milk may appear by examination to be apparently free from germs after thorough pasteurization, what of the mj^riads of dead bodies of germs killed b}^ the process which may remain in the milk ! A milk contractor in Boston sent out a laboratory report on his milk to show that before pasteurization it contained seven million germs to the quarter teaspoonful of milk and only a thousand after the process. Another serious objection to the use of pasteurized milk is the fact that its condition can not readily be discovered by ordinary tests. The lactic acid bacilli, being easily killed by heat, pasteurized milk may not show acidity or change in taste or appearance and j^et be wholly unfit for food owing to the existence of millions of germs which do not cause the milk to change but are prejudicial to health. The following method promises better than any yet known for the safe sterilization of milk. Budde's Process for Sterilizing Milk. — Fifteen c.c. (or one table- spoonful) of three per cent, solution of hydrogen peroxide are added to each quart of milk in bulk, as soon after milking as possible, and the milk is then heated to 51 deg. to 52 deg, C. (123.8 deg. to 125.6 deg. F.) for three hours. By this method the oxygen in the hydrogen peroxide is liberated by an enzyme in the milk (catalase) , with the aid of the heat, and the nascent oxygen acts as an efficient germicide. All the non-spore bearing micro-organisms are killed — including all disease germs — except those of anthrax. In fact, 99.9 per cent, of the germs in milk are destroyed by this method and nothing is left in the milk but a little water which is too small in quantity to alter the com- position of milk appreciably. The milk is unaltered in odor, taste or appearance, and the cream rises as usual while no trace of peroxide remains. Milk thus treated will, moreover, keep unchanged in warm weather for eight to ten days. This process seems to solve the question of treating dirty milk when clean milk can not be procured, and would appear to be of inesti- mable benefit in the preparation of infant's milk when of uncertain quality, and for keeping such milk to be used by an infant during a considerable journey. TLiTE XIII. —The Burrell-Lawretice-Keiiiiedv Cow Milker. The plate shows the main iron piping above the stanchions connected by rubber tubing with the pulsators placed on top of each milk pail between each two cows. Pl^ATK XIV.— The Pulsator. MILKING MACHINES Milking Machines. 189 The milking machine, together with the single service paper milk bottle, bid fair to practically revolutionize the methods of producing clean milk. If these two inventions prove as valuable as they promise, the whole question of clean milk production will be solved. The milk will be obtained nearly sterile and be immediately cooled and run into sterile bottles. The status of the milking machine seems still a matter of some uncertainty with every indication of a successful future. The machine we will describe appears to be one of the most efficient and has been in operation for some years. At present it is being used by the leaders in the dairy industrj^, as by the Walker- Gordon people and H. B. Gurler. The Burrell-Iyawrence-Kennedy Cow Milker comprises the following : 1. A vacuum pump operated by power, steam, electric motor, gas engine, tread mill (bull), a head of water over thirty feet, etc. 2. One inch iron piping connecting the vacuum pump with a vacuum tank, supplied with guage and safety valve, and thence about the barn for attachment to the milkers. 3. The Milkers. — A milker consists of a milk pail (heavy enough to withstand a vacuum), on which is placed a pulsator, which in its turn is connected with one-half inch rubber tubing to four teat cups fitted on the teats of the cow. The vacuum is about equal to one-half an atmosphere, fifteen to seventeen inches, and the vacuum tank is connected with the system to insure a uniform, safe and known suction. The pulsator (Plate XIV) is the salient feature of this machine. It rests on top of the milk pail, to which it fits tightly as soon as the exhaust is turned on, because of atmospheric pressure and because it rests on a rubber gasket. The pulsator is connected with the iron pipes which run along over the stanchions (Plate XIII) by one-half inch rubber tubing fitted to the nipple at its base. The two stop-cocks, seen in the plate of the pulsator, are each connected with rubber tubes, one taking the 190 CLEAN MILK milk from the four teats of a cow on one side, and the other from the cow to the other side of the pulsator. When the machine is in operation the cow's udder is cleaned, the teat cups (of five sizes) are adjusted, and a milk pail — placed between each two cows — is surmounted by a pulsator attached by rubber tub- ing, both to the iron piping above, and to the teats of the cows on each side (Plate XIII). That is, each milker (milk pail, pulsator, rubber connections and teat cups) is capable of milking two cows at the same time. A stop-cock is turned and the suction applied by the pulsator to the cow's teats. By this mechanism there is exerted intermittently not only suction but also compression on the outside of the teat, simu- lating the action produced in hand milking. Glass windows in the tubing leading from the teats inform the operator as to the flow of milk. Most cows do not object to the use of the machine. This machine will practically prevent the initial contamination of milk, and will render the production of clean milk more simple and eas}' than by any method heretofore known. The rubber tubing, through which the milk passes, can be sterilized and made free of germs by boiling or by steam and is kept in brine. The pulsator and milk pail can be cleaned readily by the use of boiling water or steam. As a labor-saver the device enables one man to do four men's work. One man can operate three or four milkers at once, each milk- ing two cows at the same time, which means that he can milk thirty to forty cows an hour. With hand-milking this number of cows would require the work of four men for one hour. Moreover, the results are much more uniform, and daily variations in milk-yield, depending on the personality of the milker, are eliminated. The difficulties in keeping milkers and the disastrous results from frequent change of milkers are also removed by the machine. Cost. — The expensive parts of the milking machine are the milkers and the vacuum pump, each of these costing $75 apiece. This pump is capable of operating five milkers. The entire cost of the installation, power and milking machines is estimated by the sellers MILKING MACHINES 191 to amount to about $12.00 per cow for a herd of forty cows, and $8.50 per cow for a herd of seventy-five.* With accumulating experience, the results obtained by the use of the Burrell-Lawrence- Kennedy milking machine appear to be gener- ally favorable. The more common doubts as to the amenability of cows to the milking machine, and the danger of drying up cows from incomplete emptying of the udder, have been dispelled. Cows hitherto unruly to hand milking, and heifers never milked before, have taken most kindly to the machine, and, on the whole, cows like machine milking better than hand milking. Hand stripping — after the removal of the teat cups — is done, generally, into the teat cups themselves. Cows which are milked by the machine have a longer period of lactation than when milked by hand. What appeared a serious objection to the milking machine was the complaint that the milk of single cows could not be separated from that of the herd — in case it was contaminated with blood or pus and germs from an inflamed udder ; or the milk was needed for feeding a calf ; or for making a periodical test for quantity and fat. Gurler has obviated this defect by having the pail of one machine divided into two compartments, one for each cow, and provided with corres- ponding outlets from which the milk from each cow can be drawn. Garget, and all troubles with the udder, are less frequent with the milking machine — probably because the teats are not so subject to abrasions and infection from other cows by the hands of the milker. Mr. H. B. Gurler, of Illinois, one of the most noted dairymen of this countrj^ — writing in Hoard's Dairyman — says that in thirty com- parative tests between hand and machine milking, the number of bacteria was reduced one-half by the machine — from 5,000 to 2,500 per c.c. After fourteen months' use of the Burrell-Lawrence-Kennedy machine with two hundred cows he found but two or three cows which could not be milked by it ; he gives it his unqualified approba- tion and afiirms that it has come to stay. * For details consult D. H. Burrell & Co., Little Falls, N. Y., and Brock- ville, Ont. I02 . CLEAN MILK Gurler states tliat one man with the machine is equal to three hand milkers ; that no difficulty was experienced in keeping the appara- tus clean b}^ the use of rinsing in cold water, a solution of lye, and boiling water ; and that great care should be taken in accurately fitting each teat cup to each individual teat. He warns against com- pletely filling the milk pails, lest milk be drawn into the vacuum pipes, and emphasizes the necessity of a uniform vacuum. If a teat cup pulls off or any accident occurs which reduces the vacuum, the machines should be shut off till the proper vacuum is secured. And when one of a pair of cows attached to a machine' is milked before the other, the vacuum should be shut off from that cow, at the machine, and the machine kept running until the other cow is milked. The Hegelund Method. — Extensive experiments with this method of manipulating the udder at the close of milking have been conducted by Woll at the University of Wisconsin Agricultural Station,* on one hundred and fifty cows during a summer and fall, and have proved its advantages to be as follows : A daily gain of one pound of milk, and one-tenth pound of fat per cow was obtained. This is equivalent to a gain of about thirty- five pounds of butter per cow per annum. Most cows do not object to the manipulation ; less than a dozen out of the number tested did so. The gain in quantity of milk and fat is not a temporary increase ; not only is the gain persistent, but the method tends to maintain a large flow of milk during the lactation period. The method taking the place of stripping, there is no loss of time in performing it. The use of the method develops the milk-yield of heifers, and has even doubled that of cows which have been supposed to have reached their maximum flow of milk. It increases the fat in the milk so that the yield from this method contains ten per cent, of fat. It is of great value in preventing mastitis during the early period of lactation. * Univ. Wis. Agric. Sta. Bull, No. 96. PtATE XY. (Illustrating the Hegeluiid method of mllkiug.) Fig, I. — First nianipnlation of udder, right quarters. Fig. 2. — First manipulatioH, left quarters. PW. G. 3. — Secoud nuuiipukition, right fore quarter. Fig 4. — Second nianipulatiou, right bind quarter. Fig. 5. — Second nianipiilation, right hind quarter, rear view. Fig. 6. — Third manipulation. MILKING MACHINES 193 As the method has been adopted by some of the most progressive farmers in Denmark, and this country it is well worthy of trial and is herewith described. DESCRIPTION op THE MANIPULATIONS IN THE HEGELUND METHOD OP MILKING. First Manipulation.-^ The. right quarters of the udder are pressed against each other (if the udder is very large, only one-quarter at a time is taken) with the left hand on the hind quarter and the right hand in front on the fore quarter, the thumbs being placed on the out- side of the udder and the four fingers in the division between the two halves of the udder. The hands are now pressed toward each other and at the same time lifted toward the body of the cow. This press- ing and lifting is repeated three times, the milk collected in the milk cistern is then milked out, and the manipulation repeated until no more milk is obtained in this way, when the left quarters are treated in the same manner. (See Plate XV, Figs, i and 2.) Second Manipidatiofi. — The glands are pressed together from the side. The fore quarters are milked each by itself by placing one hand, with fingers spread, on the outside of the quarter and the other hand in the division between the right and left fore quarters : the hands are pressed against each other and the teat then milked. When no more milk is obtained by this manipulation, the hind quarters are milked by placing a hand on the outside of each quarter, likewise with fingers spread and turned upward, but with the thumb just in front of the hind quarter. The hands are lifted and grasp into the gland from behind and from the side, after which they are lowered to draw the milk. The manipulation is repeated until no more milk is obtained. (See Plate XV, Figs. 3-5.) Third Manipulation. — The fore teats are grasped with partly closed hands and lifted with a push toward the body of the cow, both at the same time, by which method the glands are pressed between the hands and the body ; the milk is drawn after each three pushes. When the fore teats are emptied, the hind teats are milked XU the same manner, (See Plate XV, Fig. 6.) 194 CLEAN MILK Standardizing Milk It may be desirable to produce a milk standardized to contain a fixed and constant percentage of fat. This is particularly important for infant feeding. Or one may wish to supply a milk of unusual and definite richness ; or again one may want to combine two lots of cream of different fat percentages to obtain a cream of definite percentage. A very simple method of determining what amount of any given two lots of milk or cream, varying in richness, is required for combina- tion to obtain a milk or cream of definite fat percentage is given below. This method of standardizing milk was devised by Prof. R. A. Pearson, of Cornell University. One should construct a figure like the accompanying cut, and in the two left hand corners write the percentages of fat in the two lots of milk (or cream and milk, or two lots of cream, as the case may be). In the centre, place the percentage of fat required. At the right hand corners write numbers which will be the differences between two numbers with which they stand in line. Thus: If 4.7 and 3.4 are the percentages of fat in two lots of milk — and it is desired to make a mixture containing four per cent, of fat — subtract 4 from 4.7 and place the result (.7) at the lower right, hand corner. Subtract 3.4 from 4 and place the result (.6) at the upper right hand corner. The result shows that it will take six parts of 4.7 per cent, milk, and seven parts gf 3.4 per cent, milk, to make a standard four per cent, milk. STABLE VENTILATION 195 A New Method of Stable Ventilation. Quite recently there has come into existence a new system of ventilating barns by means of windows covered with cheap cotton cloth. No method could be simpler or less expensive abd the results thus far reported have been very favorable. Thus Ellis M. Santee, of the Dairy Department of Washington, D. C, writing in Hoard's Dairyman of May 17th, 1907, records some conclusions from exhaustive experiments with cloth ventilation as compared with the King system. He affirms that even with the thermometer registering 43 degrees below (zero, presumably), water never froze in the barn with cloth-covered windows. Also that the difference in temperature in barns with cloth-covered windows and in those with all glass windows was but i to 3 degrees. Moreover, in the stables ventilated with cloth-covered windows, the humidity was 7 to 10 per cent, lower than in the barns ventilated by the King system. Finally he records the fact that many good dairymen have closed the outlets and inlets of their King system to give place to the cloth curtahi method. Glass windows should be alternated with cloth- covered openings, the proportion being 3 sq. ft. of glass and 2 sq. ft. of cloth-covered openings for each 1,000 lbs. of animal. The cloth should be muslin of the first grade better than cheesecloth, costing 5 to 6 cents par yard. Method of Keeping Accounts of the Pure Milk Dairy {^Sce the following three for vis.') I MAPLEWOOD FARM Daily Milk Report 1907 Empty cases received last train Bottles short last train . . . Bottles broken wlieu received Bottles broken at farm . . . Cases milk shipped to-day. . , , , and Qts. 196 CLEAN. MILK Explanation. — The foregoing report is signed by the manager at the farm. It shows the number of empty cases (holding 12 quart bottles) received from the city and the number of bottles broken and missing in them. Also the number of full cases shipped to the city. II Driver. . . . Route No. MILK RECEIVED CASH ACCOUNT Received from Ry Milk Cream Quarts Gals. Pints M Pints Paid ox Account « Delivered Milk Cream \i Pints Paid for Tickets $ Returned Milk Quarts Cream Pints 1^ Pints ' * Bottles Delivered Cash Receipts. .% Total |.... Bottles Returned f f ♦ This blank is filled out daily by the driver of each delivery wagon . and represents, first, the amount of milk and cream received from railway; second, the amount of milk and cream delivered to customers ; third, the amount of the same brought back to the store ; fourth, the bottles delivered to and returned by customers ; and fifth, the casU paid for accounts due or tickets, METHOD OF KEEPING ACCOUNTS III. ^97 fS 1 ;2 1 n •a I t s s & R R R R ft ;S A ,S n , H R S £ X '■ p» :S a s m C C o ©• te (> £ ifi «> m N - 1 ii III ill tin This form represents a loose card, one of which is devoted to each customer for a year. The day's sales of the drivers of the milk wagons are copied off their books each day and kept in the ofi&ce of the city dairy in this form, 198 CLEAN MILK A General Outline of a Scheme for the Control, Supervision and Inspection of a City Milk Supply The legal control of a city milk supply is in the hands of the City Board of Health. The State Board of Health should, however, work in cooperation with the City Board through its jurisdiction over the territory from which the milk is obtained. When the milk is drawn from several states this is, of course, of but slight value. Moreover, state supervision is not essential, since the city authorities can enforce sufficient influence over the producer of unsanitary milk in the following ways : By condemning such when it arrives in the city ; by warning or fines ; by revoking the license of the dealer in the same in the city ; and by requiring that the premises on which the milk is produced be inspected before the milk can be sold in the city. Supervision of a milk supply must begin at the barn and be continued until the milk reaches the consumer. Thus milk must be inspected at the following points : 1. At the farm. 2. During transportation from the farm to the R.R. or creamery. 3. At the creamery, when this is the shipping point. 4. On the cars during transportation to the city. 5. At the city R.R. or receiving station. 6. On the wagon in the city. 7. At the city dairy, hotel, restaurant, retail store and home of the consumer. The country furnishing milk must be mapped, the farms and creameries from which milk is shipped must be plotted, and the territory divided into districts, each under the supervision of an inspector living in the region. It has been recommended that there be one inspector to each 100 farms. At present New York City has about 100 inspectors (1907) to supervise some thirty to forty thousand farms in six states and shipping milk into the city from points four hundred miles distant. No milk should be permitted to enter a city until the seal of inspection has been first placed upon it by an inspector in the country. GENERAL OUTLINE 199 When milk is shipped from creameries or country receiving stations these form convenient points for inspection and also serve as a base for investigation of the farms supplying the creameries. At the creameries the following demand looking into : (i) The cleaning and sterilization of all utensils ; (2) the water supply and drainage ; (3) the temperature at which milk and cream are kept ; (4) general cleanliness, requiring the absence of flies and dust. The farms need inspection in regard to the ensuing matters : Cleanliness of the cows, milkers and other employees ; of the barn, milk house, utensils and surroundings ; the health of the employees and cows, with especial attention to infectious diseases in the former, and to tuberculosis and udder disease (garget) in the latter ; the kind of food given to cows (avoidance of swill, fermented brewers' grains and distillery slops, etc.) and time of feeding ; the purity of water and ice supply, ventilation of barns, removal of manure, drainage of premises, and methods of milking and handling and cooling milk. Also the method of storing and caring for milk and hauling it to the R.R. or creamery ; and the care of the milk room, especially with regard to the absence of dust and flies. Inspections of creameries and farms should be made once a month at least, and reports should be rendered in quadruplicate, one of which should be sent to the city ofiice, one to the farmer, one to the retail dealer selling the milk, and one to be retained on file in the local office in the country. This suggestion was made by Dr. Goler, of Rochester, N. Y., who also recommends, in case the territory supply- ing a city is 'large, the establishment of one or more laboratories in the country as sub-stations for the work of milk inspection. This might be conveniently carried out in connection with creameries. Country inspectors should not only perform their police duties, but should act as teachers and should talk and distribute printed matter concerning everything which relates to the production and care of sanitary milk. The plan adopted by the Massachusetts Board of Health, in publishing a monthly list of well conducted and cleanly farms, is to be commended. Goler urges the establishment of model dairy farms by the State in connection with the laboratory substations in the country, 200 CLEAN MILK the scheme comprising the remodeling of some old and run-down farm, so that in its upbuilding the farmer could apply the same measures to his own premises. In regard to the carriage of milk on the railroad, railways carrying milk to the large cities of the country now supply refrigerator cars for milk, with adequate icing facilities to cool milk below 50° F., in most cases. When such refrigerating arrangements are not obtain- able, milk and cream should be shipped as advised on p. 87. Inspection on the cars is limited to taking the temperature of milk. At the receiving station in the city there must be daily inspection with reference to the temperature of milk, to the care of cans and bottles of milk while en route, and to the condition of empty bottles and cans which are being returned. The inspector shall here examine milk by sight, smell and taste, and by lactometer and lactoscope (if such be the custom), and take samples for laboratory examination. According to the writer's views, the only accurate testing which should be done by the collectors of samples is that of temperature taking. Testing for the solids and fat and for adul- teration and bacterial content can be done much more accurately at the laboratory. During distribution of milk by wagon in the city, inspection is desirable to ascertain that the milk is properly iced in warm weather, that the temperature of the milk is kept below 50° F. , that bottling of milk is not done on the wagon, and that general cleanliness of utensils and wagon is observed. Samples of milk should be taken from each wagon at least once a month for laboratory examination. A sample of milk should be taken from each retail store every month. Milk in the various stages of transportation from cow to consumer becomes more germ-laden through age and handling, espe- cially when poured from one utensil to another, and the case of the retail shop is the worst. This has been strikingly shown by Prof. J. O. Jordan, of Boston. The legal limit for bacterial content in Boston is 500,000 germs to the c.c. The milk during 1906, in respect to this standard, was found to be distributed as follows : On the cars, on arrival, 90 per cent, under germ standard {i.e., con- taining not less than 500,000 bacteria) ; on the wagons, 50 per cent. GENERAL OUTLINE 201 under germ standard ; in the retail stores, 18 per cent, below germ standard. Such a difference between the quality of milk on arrival and subsequently does not occur in milk bottled at the farm, cooled immediately below 50° F. and kept at that point all the time until it reaches the store customer. Only bottled milk should be sold in stores, and the bottling should be done at the farm or, less favorably, at the creamery or city dairy. Inspection at stores must enforce requirements for a proper refrigerator and cooling of the milk, and also that the store be apart from dwelling rooms. In the inspection of city dairies, stores, hotels and restaurants, the proper cleaning of empty cans and bottles should receive special attention. In many cities an ordinance requires that milk cans and bottles must be thoroughly cleaned or sterilized before their return to the farm or creamery. Also an ordinance should forbid using utensils employed for transporting milk and cream as receptacles for any other material whatsoever. Jordan notes that broken eggs, coffee, oil, chocolate, molasses, blood, and, above all, kerosene, are not infre- quently discovered in milk cans. At each city dairy the cleanliness of premises and milk utensils, the purity of the water supply, and the facilities and method of cooling milk and cream should be the subjects of inspection. Samples of milk should be taken from the city dairy at least once monthly. Inspection of milk at hotels and restaurants should be directed toward enforcing the ordinances as regards temperature of milk, cleanliness of utensils and the sale of skim milk. Samples should be taken once a month from hotels and restaurants. The proper care of milk affer it has reached the consumer is the most difficult matter of control and can only be managed by general education of the public. The Board of Health, through its monthly bulletins, and those selling clean milk may supply the public with information on the subject, and consumers should be fined for not returning empty milk bottles or cans properly cleaned. Jordan points out another objection to the popular desire for the early arrival of milk we have noticed (p. 125): that milk left on the doorstep in the early morning hours of summer may be heated by the sun to an injurious degree. At this place it may not be out of 26^ CLEAN MILK order to note that the forms fiirnished by the City Board of Health to physicians for compulsory reports of infectious diseases should require the name of the milkman supplying each infectious case reported. In Boston the wholesale milk dealers are exceptionally progressive. They assist the health authorities by taking the temperature of milk consigned to them, by straining milk to discover dirt, by cleaning empty cans; while six dealers (1907) have actually installed bac- teriological laboratories for their own use (Jordan). A sufficient number of inspectors or collectors of samples in cities may require one to each 50,000 of population. In addition to the duties described above, the city inspector should examine the premises of applicants for a city license to sell milk, before one may be issued. The City Board of Health should publish in a monthly report the names of each dairyman, dividing them into four categories : those selling Certified, Inspected, Ordinary Market and Pasteurized milk ; and should report the number of bacteria in each. Also notice of any dairyman who has been found guilty of infractions of any of the ordinances pertaining to milk should be thus publicly announced. A. D. Melvin, Chief of the Bureau of Animal Industry, suggests that the following division be made of the milk composing a city supply: I. Certified milk. 2. Inspected milk from tuberculin-tested cows housed, fed and milked under good conditions with a maximum content of 100,000 germs per c.c. the year round, and shipped in sterilized containers at the farm at a temperature below 50° F. 3. All other milk should be pasteurized (as soon as practicable after milking at 154° F. for twenty minutes), cooled immediately and sold in sterilized containers at a temperature below 50° F. INDEX Pago Acidity of milk, test for 138 of pasteurized milk 138 Air space in barn 58 Analysis, quantitative, of bacteria 149, 161 Anthrax affecting milk 20 Albumin of milk 24 Ayrshire cows 169 Babcock test for fat in milk. . .141, 146 Bacteria, see Germs. analysis of milk for 149, 161 Balanced rations, selection of. . . . 49 specimens of 51 Barn dust 66 floors 58 plans of 178-187 ventilation of 59, 195 Barns 57 Beasiings 30 Bedding 67 Bitter milk 18 Blue milk T 18 Bookkeeping, city milk route 195 Borax in mil k 136 Boric acid in milk 136 Bottle boxes 127 brushes 93 filler 89 washer 95 Bottled milk, cooling 84 Bottles, milk 104, 105 to prevent loss of. 1 29 Bottling milk 96 utensils for 87 Brown milk 18 Brushes for cleaning milk uten- sils 87, 94 Burrell - Lawrence milking ma- chine 189 Page Butter, action of germs on 2 composition of 43, 118 fat, how to pay creamery pa- trons for 120 flavor 37 from fresh cream 38, 41 skim milk 43 making, losses in 1 19-122 making, overrun in 119 milk, composition of 43 Budde's process of sterilizing milk 188 Bye-products of milk 44 Caps for milk bottles 130 Carriers for milk bottles 102 Cars for milk 103 Certified milk, circular describing 131 cost of 114 how to begin sa'e of. 117 price of 116 New York requirements i6r standard and origin of 16 Cheese, action of germs on 2 composition of 43 hard 41 making 41 ripening 41 soft 41 Cholera, infecting milk 21 Cleaning cows ,. . 70 utensils 85 Cloth ventilation of barns 195 Clothing for milk room 98 Colostrum 30, 135 as source of disease 31 Commercial starters, Harrington's 39 Composite samples of milk 177 Composition of butter 43 butttermilk 26 cheese .... ?4 204 INDEX Page Conposition of colostrum 31 cream 36 milk 23, 26 affected by excitement. . . 29 exposure 29 food 29 fright 29 milking 29 period of heat 29 period of lactation. . . 29 surroundings 29 season 29 treatment 29 skim milk 26,36 whey 43 Concentrates 51 Condensed milk, action of germs on 2 Coolers, milk 71-83 Star 80 tubular 80 Cooling bottled milk 84 of milk 77 Cost of certified milk 114 Cow, annual cost of 113 Ayrshire 169 care of 69 census no, in for milk 169 dairy, characteristics of 169 dehorning 174 grooming 70 Guernsey 169 Holstein 169 Jersey 169 number of in barn 59 pox, affecting milk 20 profits no rations 174 records 173 how to keep 176 returns from no standard for 112 stall 177 value of 177 Cream, acidity of for butter 139 bottling 108 conditions favoring rising. ... 33 dipper for removing 132 set, germs in — 37 Page Cream per cent, of solids in 36 ripening of 37 separation of 107 starters 39 thickeners 108, 140 whipping 109 Culture media for bacteriological analysis 149 Curdling of milk 25 Dairy, arrangement of. 99-102 cows , . . 169 routine 96 utensils, washing of 98 Dehorning cows 174 Diarrhea of infants from milk. ... 22 Diphtheria infecting milk 21 Drivers' uniform 131 Dust in barn 66 milk room 76 Dysentery infecting milk 21 Ensilage affecting milk 54 Farrington's acidity test 158 Farrington on starters 39 Fat of milk 25 Fat in milk and cream, test for, 141-146 Feeding, balanced ration for 49 concentrates 51 Haecker's rules for 50 for milk 46 of silage 54 in relation to milking 54 roughage 51 specimen ration for 51 Fishy milk 85, 135 Flies in barn 66 spray for on cows 66 Food, influence on lactation period 47 imparting flavor to milk 56 imparting taste to milk 54 Foot and mouth disease affecting milk 20 Formaldehyde in milk 136 Freezine 10 Gelatine in milk. 141 Garget affecting milk 20 Germs, acids and alkalies affecting 6 INDEX 205 Page Germs, action on butter, cream, cheese, milk, condensed milk. . 2 action of temperature on 6 causing flavor of butter 38 characters of 3 conditions of growth 5, 17-18 in barn 67 in filtered milk ? 35 in cheese ripening, 42 in market milk 17 in separated cream 35 influence on milk and products 12 lactic acid 13 action on man 13 flavoring butter & theese 13 miscellaneous 15 flavoring butter 38 moisture affecting growth of. 6 multiplication of, 4 number present in clean milk 1 1 of butyric acid 18 of disease in milk 15 of tuberculosis in milk iq putrefactive 15 significance of, in milk 11 numbersinmilk 15 quantity and variety in milk 15 sunlight affecting 6 standard for water supply 53 temperature affecting growth 5 test for 149-161 Green milk 18 Grooming cows 70 Guernsey cows 169 Gutters for manure 59 Haecker's rules for feeding 50 Heating water 95 for dairy 85 Hegelund method of stripping cows 192 Holsteiu cows 169 Iceline 10 Infant mortality 22 Inspected milk, New York require- ments 165 Inspection of milk 134 Jersey cows 169 Page Keeping qualities of milk 14 King system, ventilation 59 Lactation period of cows 29 increased by feeding 47 Lactic acid germs 13 action on man 13 in fermentation of milk 24 flavoring butter and cheese, 13, 38 killing other germs 13 Lactometer 146 Machine, milking 189 Manure, removal of from barn . . 66 trench 59 Market milk, germs in 17 Miscellaneous germs 15 Modified milk, for infants 137 Milk acidity, test for 137 action of temperature on 14 adulterated with borax 136 adulteration, boric acid 136 formaldehyde, orfreezine 136 salicylic acid 137 sodium carbonate 137 as a source of infant mortality 22 as a source of diarrhea 22 as a source of cholera infantum 22 bacteria, analysis of 149-161 bad odor of 135 bad taste of ., 135 bitter 18 blue 18 bookkeeping for city route. . . 195 bottle 104 caps 130 carriers 102 cars 103 shipping cases 103 to prevent loss of 129 bottling of 96 utensils for 87 boxes, for bottles 127 brown 18 bye products in manufactures 44 certified 16 certified, cost of. 114 N. Y. requirements for . . 161 price of 116 composite samples of 177 2o6 INDEX Page Milk, composition ol 23 coolers 78 cooling of. 77 condensed, action of germs on 2 curdling of 25 dirt m 135 dirty, a source o ftyrotoxicon 22 during tuberculin test 56 fat 25 test for 141-146 feeding affecting composition of. 46 feeding for 46 fever, afifecting milk 20 treatment of. 69 fishy 53, 85, 135 from silage 54 formation in udder 46 green 18 hints in delivery 129 house, arrangements of 99 plans of 17S-187 in anthrax 20 in cow pox 20 foot and mouth disease. . 20 garget 20 milk fever 20 pleuropneumonia 20 inspected, N. Y. requirements 165 inspection 134 keeping qualities of. 14 modified for infants 131 pails 73-74 pasteurized 7-10, 187 preservatives 10 tests for 136, 137 proteids 24 pus in, test for 160 records 112, 176 red 18 returns from selling in various forms 123 room 75 utensils for 76 samples 135, 136 siphon for removing from bottle 132 skim, food value of 43 test for 141 slimy 18 Page Milk soapy 18 solids, estimation of. 146 souring of 24 standard for cow 112 standardizing 194 sterilizing, Budde's process. . 188 sterilizers for utensils 89 stirrer 97 strainer 84 stringy 18, 135 strippings 27 sugar 24 sweet 10 time of delivery 126 utensils, washing 93 wagons 127 watered, test for 141 yellow 18 Milkers, cleanliness of 71 Milking 71 as affecting composition of milk 2S in relation to feeding 54 machine 189 Overrun 118 how to estimate 119 Pails, milk 73-74 Paper milk bottle 105 Pasteurized milk 7-10, 187 acidity of 138 test for 137 Plans of barns 178-187 Pleuropneumonia affecting milk. . 20 Preservatives 10 tests for 136 Price of certified milk 116 Proteids in milk 24 Putrefactive germs 15 Records of cows 176 of milk .112, 176 Red milk 18 Room, milk. 75 Roughage 15 Salicylic acid 137 Scarlet fever infecting milk 21 Separation of cream , 107 INDEX 207 Page Separation, removing germs 35 removing dirt 35 Separator cream 34 slime 34 Separators, management of 175 Shipping cases 103-104 Skim milk, food value of 43 test for 141 value of J 24 Slimy milk 18 Smallpox infecting milk 21 Soapy milk 18 Sodium carbonate in milk 137 Solids in milk 146 Souring of milk 24 Stalls 65,58 Stanchions 65 Standardizing milk 194 Star cooler 80 Startolene 40 Starters, natural and commercial. 39 Sterilizers 89 Straining , 84 Stringy milk 135, 18 Stripping cows, Hegelund method 192 Strippings of milk 27 Sugar of milk 24 Temperature affecting milk 14 Test, acidity of milk 137 for gelatine 141 Page Test for preservatives in milk . . .136-7 for pus in milk 160 for viscogen in milk 140 Tie-ups 65 Tuberculin test 20, 56, 69 Tuberculosis, germs of in milk . . 19 Tubular coolers 80 Typhoid fever infecting milk 2 [ Tyrotoxicon in milk 22 Utensils, cleaning 85 in milk room 76 Ventilation of barns 59, 195 King system of 59 Viscogen in milk 108, 140 Wagons, milk 271 Washing dairy utensils 98 milk utensils 93 sink 94 Water, germ standard for 53 for dairy use 21 heating 85, 95 Watered milk, test for 141 Water supply 53 Water, stagnant, in pastures. ... 53 Whey, composition of 43 Whipping cream 109 Yellow milk 18 CATALOGUE OF William R. Jenkins Co/s Works Concerning HORSES, CATTLE, SHEEP, SWIHE, Etc. 1908 (*) Designates Neio Books. (I) Designates Recent Publications . ANDERSON, "Vice in the Horse" and other papers on Horses and Riding. By E. L. Anderson. 8ize, 6x9, cloth, illustrated '. 1 75 ARMSTEAD. "The Artistic Anatomy of the Horse." A brief description of the various Anatonjical Struc- tures which may be distinguished during Life through the Skin. By Hugh W. Armstead, M.D., F.E.C.S. With illustrations from drawings by the author. Cloth oblong, 10 x 12^ 3 75 BACH. " How to Judge a Horse." A concise treatise as to its Qualities and Soundness ; Including Bits and Bitting, Saddles and Saddling, Stable Drainage, Driv- ing One Horse, a Pair, Four-in-hand, or Tandem, etc. By Capt. F.W.Bach. Size, 5 x7i, clo., fully illus.l 00 BANHAm. "Tables of Veterinary Posology and Thera- peutics," with weights, measures, etc. By Geo. A. Banham, F. R. C. V. S. New edition. Cloth, size 4x5 1-2, 192 pages 1 00 BAUCHER. "Method of Horsemanship." Including the Breaking and Training of Horses. By F. Baucher 1 00 BELL. (*)"The Veterinarian's CaU Book (Perpetual)." By Roseoe R. Bell, D.V.S., editor of the American Veterinary Review. Completely revised 1907. A visiting list, that can be commenced at any time and used until full, c(>ntaining much usefulinforma- tion for the student and the busy practitioner. Among contents are items concerning : Prescription writing; Veterinary Drugs; Poisons; Solubility of Drugs; Composition of Milk, Bile, Blood, Gastric Juice, Urine, Saliva; Respiration; Dentition; Temp- erature, etc., etc. Bound in flexible leather, with flap and pocket , 1 26 BITTING. *' Cadlol's Exercises in Equine Surgery." See "Cadiot." BRADLEY. " Outlines of Veterinary Anatomy." By O.Charnock Bradley, Member of the Koyal Col- lege of Veterinary Surgeons ; Professor of Anatomy in the New Veterinary College, Edinburgh. The author presents the most important facts of veterinary anatomy in as condensed a form as possible, consistent with lucidity. 12mo. Complete in three parts. Pakt I. : The Limbs (cloth) 1 25 Pakt II. : The Trunk (paper) 1 25 Part III. : The Head and Neck (paper) 1 25 The Set compijEte 3 25 CADIOT. " Exercises in Equine Surgrery." By P. J. Cadiot. Translated by Prof. A. W. Bitting, D.V.M. Edited by Prof. A . Liautard, M.D. V.M. Size, 6 x ^%. cloth, illustrated 2 50 — "Roaring in Horses." Its Pathology and Treatment. This work represents the latest development in oper- ative methods for the alleviation of roaring. Each step is most clearly defined by excellent full-page illustrations. By P. J. Cadiot, Professor at the Veterinary School, Alfort. Translated by Thos. J. Watt Dollar, M.R.C.V.S., etc. Cloth, size 5 1-4 x 7 1-8, 77 pages, illustrated 75 — "Studies in Clinical Veterinary Medicine and Surgery." By P. J. Cadiot. Translated, edited, and supplemented with 49 new articles and 34 illustrations by Jno. A. W. Dollar, M.R.C.V.S. Cloth, size 7x9 3-4, 619 pages, 94 black and white illustrations 5 25 —(•)" A Treatise on Surgical Therapeutics of the Domestic Animals." By F. J. Cadiot and J. Almy. Translated by Prof. A. Liautard, M.D. , V.M. I. General Surgery. — Means of restraint of animals, general anaesthesia, local ansethesia, surgical anti- sepsis and asepsis, hematosis, cauterization, firing, II. Diseases Common to all Tissues. — Inflammation, abscess, gangrene, ulcers, fistula, foreign bodies, traumatic lesions, complications of traumatic les- ions, granulations, cicatrices, mycosis, virulent dispases, tumors. III. Diseases Special to all Tissues and Affections of the Extremities. — Diseases of skin and cellular tis- sue, of serous bursae, of muscles, of tendons, of tendinous svnovial sacs, of aponeurosis, of arteries, of veins, of lymphatics, of nerves, of bones, of articulations. Cloth, size 6x9, 580 pages, 118 illustrations 4 50 CHAPMAN. "Manual of the Pathological Treatment of I>amenes8 in the Horse," treated solely by mechanical means. By George T. Chapman. Cloth, size G X 9, 124 pages with portrait 2 00 CLARKE. "Chart of the Feet and Teeth of Fossil Horses." Hy W. H. Clarke. Card, size 9 1-2 x 13. . ^5 —"Horses' Teetli." FourLli edition, re-revised, with second appendix. Cloth, size 5 1-4 x 7 1-2, 322 pp., illus..2 50 CLEAFELAND. " Proiiounciiig' Medical Lexicon," F<)ck^-t edition. By C H. Cleveland, M.D. Cloth, size 3 1-4x4 1-2, 3U2 pages 76 CLEMENT. " Veterinary Post Mortem Examina- tions." By A. W. Clement, V.S. The absence in the English language of any guide in making autopsies upon the lower animals, induced Dr. Clement to write this book, trusting that ii would prove of prac- tical value to th« profebtion. Cloth, size 5x7 1-2, 64 pages, illustrated 75 CO URTENA r. f f ) " Manual of the Practice of Veterinary Medicine." Hy Edward Courtenay, V.8. Kevised by Fi-ederick T. G. Hobday, F.R.C.V'.S. Second edition. Cloth, size 5 1-4x7 1-2, 573 pages 2 75 COX. " Horses : In Accident and Disease." The sketches introduced embrace various attitudes which have been observed, such as in choking ; the disorders and accidents occurring to the stomach and intestines ; afTection of the brain ; and some special forms of lame- ness, etc. By J. Roalfe Cox, F.R.C.V.S. Cloth, size 6 x 9, 28 full page Illustrations 1 50 DALRY3IPLE. (*)"Veteri nary Obstetrics." A compen- dium for the use of advanced students and Practi- tioners. By W, H. Dalrymple, M. K. C. V. S., principal of the Department of Veterinary Science in the Louisiana State University and A. & M. College; Veterinarian to the Louisiana State Bureau of Agriculture, and Agricultural Experiment Stations. Second edition revised. Cloth, si-^.e 6x9 1-4,162 pages, 51 illustrations 2 50 DALZIEL. "Breaking and Training Dogrs." Part I, by Pathfinder. Part II, by Hugh Dalziel. Cloth, illustrated 2 50 — " The Collie." By Hugh Dalziel. Paper, illustrated 50 — "The Diseases of Dogs." Causes, symptoms and treatment. By Hugh Dalziel. Illustrated. Paper, 50c. Cloth, 1 fO — "Diseases of Horses." Paper 50 — " The Fox Terrier." By Hugh Dalziel. Paper, 50; clo.l 00 — "The Greyhound." Cloth, illus 1 00 — " The St. Bernard." Cloth, illustrated , , , X 00 DANA. "Tables in ComparatiTe Phygiology." By Prof. C. L. Dana, M.D. Cbart, 17 x 17 26 DAKCE. " Veterinary Tablet." By A. A. Dance. Chart, 17 X 24, mounted on linen, folded in a cloth case for the pocket, size 3 3-4 x 6 1-2. Sho^s at a glance the eynopsis of the diseases of horses, cattle and dogs; with their cause, symptoms and cure 75 DE BRUIN. (*)" BoTine Obstetrics." By M. G. De Bruin Instructor of Obstetrics at the State Veterinary School in Utrecht. Translated by W. E. A. Wyman, formerly Professor of Veterinary Science at Clemson A. & M. College, and Veterinarian to the South Carolina Experiment Station. Cloth, size 6x9, 382 pages, 77 illustrations 5 00 Synopsis of the Essential Features of the Work 1. Authorized translation. 2. The only obstetrical work which is up to date. 3. Written by Europe's leading authority on the subject. 4. Written by a man who has practiced the art a lifetime. 5. Written by a man who, on account of his eminence as bovine practitioner and teacher of obstetrics, was selected by Prof. Dr. FrOhner and Prof. Dr. Bayer (Berlin and Vienna), to discuss bovine obstetrics both practically and scientifically. 6. The only work containing a thorough dififerential diag- nosis of arte and post partura diseases. 7. The only work doing justice to modern obstetrical surgery and therapeutics. 8. Written by a man whose practical suggestions revolu- tionized the teaching of veterinary obstetrics even in the great schools of Europe. 9. The only work dealing fully with the now no longer obscure contagious and infectious diseases of calves. 10. Absolutely original and no compilation. 11. The only work dealing fully with the difficult problem of teaching obstetrics in the colleges. 12. The only work where the practical part is not over- shadowed by theory. ... A veterinarian, particularly if his location brings him in contact with obstetrical practice, who makes any pretence toward being scientific and in possession of modern knowledge upon this subject, will not be without this excellent work, as- it is really a very valuable treatise.— Pt'o/. Boscoe B. Bell, in the Americaji Vetennary Bevieiv. In translating into English Professor De Bruin's excellent text- book on Bovine Obstetrics, Dr. Wyman has laid British and American veterinary surgeons and students under a debt of gratitude. The works represents the happy medium between the booklets which are adapted for cramming purposes by the student, and the ponderous tomes which, although useful to the teacher, are not exactly suited to the requirements of the everyday practitioner . . . We can strongly recommend the work to veterinary students and practitioners.- T/ie Journal of Comparative Pathology and Therapeutics. DOLLAR. f." Diseases of Cattle, Sheep, Goats and Swine." By G. Moussu and Jno. A. W. Dollar, M.R.C V.S. "Size 6x9 1-2, 7*»5 pages, 329 illustrations in the text and 4 full page plates 8 75 — (f)"A Hand-book of Horse-Sboeing," with introductory chapters on the anatomy and physiology of the horse's foot. By Jno. A. W. Dollar, M.RCV.S., with the collaboration of Albert Wheatley, F.R.C.V.S. Cloth, size 6x8 1-2, 433 pages, 406 illustrations . .4 75 DOLLA.R (continued) — (t/'Operative Technique." Volume 1 of "The Practice of Veterinary Surgery." Cloth, size 6 3-4 x 10, 26i pages, 272 illustrations 3 75 — *' General Surgery." Volume 2 of " The Practice of Veter- inary Surgery." In preparation. — (t)" Regional Veterinary Surgery." Volume 3 of "The Practice of Veterinary Surgery." By Drs. Jno. A. W. Dollar and H. MoUer. Cloth, size 6 1-2 x 10 853 and xvi pages, 315 illustrations 6 25 — *'Caiiot's Clinical Veterinary Medicine and Surgery," See " Cadiot." — "Cadiot's Roaring in Horses." See " Cadiot." DUN. "Veterinary Medicines, their Actions and Uses." By Finlay Dun, V.S., late lecturer on Materia Medica and Dietetics at the Edinburgh Veterinary College, and Examiner in Chemistry to the Koyal College of Veterinary Surgeons. Edited by James Macqueen, F.R.C. V.S. Tenth revised English edition. Cloth, size 6x9 3 75 FLEMING. "The Contagious Diseases of Animals." Their influence on the wealth and health of nations and how they are to be combated. Paper, size 6x7 1-2, 30 pages 26 — " Human and Animal Variolse." A Study in Comparative Pathology. Paper, size 5 1-2x8 1-2, 61 pages ... 25 — "Parasites and Parasitic Diseases of the Domesticated Animals." By L. G. Neumann. Translated by Dr. Fleming. See " Neumann" — "Operative Veterinary Surgerjr," Vol. I, by Dr. Geo. Fleming, M.R.C.V.S. This valuable work, one of the most practical treatises yet issued on the subject in the English language, is devoted to the common opera- tions of Veterinary Surgery ; and the concise descrip- tions and directions of the text are illustrated with numerous wood nngravings. Cloth, size 6x9 1-4, 285 and xviii pages, 343 illustrations 2 75 (•)Vol. II, edited and passed through the press by W. Owen Williams, F.R.C. V.S. Cloth, size 6x9 1-4, 430 and xxxvii pages, 344 illustrations 3 25 — '* Roaring in Horses." By Dr. George Fleming, F.R C.V.S. Its history, nature, causes, prevention and treatment. Cloth, size 5 1-2x8 3-4, 160 pages, 21 engravings, 1 colored plate 1 50 — " Veterinary Obstetrics." Including the Accidents and Dis- eases incident to Pregnancy, Parturition, and the Early Age in Domesticated Animals. By Geo. Fleming, F.R.C.V.S. Cloth, size 6x8 3-4, 758 pages, illu8.6 25 GOTTHIEL. (*)"A Manual of General Histology. By Win. S. Gottheil, M.JJ., Professor of Pathology in the American Veterinary College, New York; etc., etc. Histology is the basis of the physician's art, as Anatomy is the foundation of the surgeon's science. Only by knowing the processes of life can we under- stand the changes of disease and the action of remedies; as the architect must know his building materials, so must the practitioner of medicine know the intimate structure of the body. To present this knowledge in an accessible and simple form has been the author's task. Second edition revised. Cloth, size 5 J-2 x 8, 152 pages, 68 illustrations. . . 1 00 ORES SWELL. " The Bovine Prescriber." For the use of Veterinarians and Veterinary Students. Second edition i-evised and enlarged, by James B. and Albert Gresswell, M.R.C.V.S. Cloth, size, 5x7 1-2, 102 pages 75 — "The Equine Hospital Prescriber." For the use of Veter- inary Practitioners and Students. Third edition re- vised and enlarged, by Drs. James B. and Albert Gresswell, M.R.C.V.S. Cloth, size 5x7 1-2, 165 pages 75 — "Diseases and Disorders of the Horse." A Treatise on Equine Medicine and Surgery, being a contribution to the science of comparative pathology. By Albert, Jas. B. and Geo. Gi'^sswell. Cloth, size 5 3-4 x 8 3 4, 227 pages, illustrated 1 75 — Manual of "The Theory and Practice of Equine Medicine." By James B. Gresswell, F.R.C.V.S., and Albert Gresswell, M.R.C.V.S. Second edition revised. Cloth, size 5 1-4x7 1-2, 539 pages 2 75 — (t) "Veterinary Pliarniacopieia and Manual of Comparative Therapy." By George and Charles Gresswell, with descriptions and physiological actions of medicines, by Albert Gre.«.=iwell. Second edition revised and enlarged. Cloth, 6x8 3-4, 457 pages 3 60 HASSLOCH. " A Conipend of Veterinary Materia Medica and Therapeutics." By A. C. Hassloch, V.S., Lecturer on Materia Medica and Therapeutics, and Professor of Veterinary Dentistry at the New York College of Veterinarv Surgeons and School of Compa- rative Medicine, N. Y. Cloth, size 5 1-4x7 1-2, 225 pages 150 HEATLEY. " The Stock Owner's Guide." A handy Medi- cal Treatise for every man who owns an ox or cow. Bv George S. Heatley, M.R.C.V.S. Cloth, size 5 1-4 X 8, 172 pages 1 25 HI1.L. (f.)"Tlie Diseases of the Cat." By J. Woodroffe Hill, F.K.C.V.S. Cloth, size 6 1-4x7 1-2, l^S pases, lUusirated 1 25 Written from the experience of raany years' prac- tice and close pathological research into the maladies to which our domesticated feline friends are liable— a subject which it must be admitted has not found the prominence in veterinary literature to which it is undoubtedly entitled. — "The Management and Diseases of the Doff ' Bv J Woodroffe Hill, F.R.C.V.S. Cloth, size 5 x 7 1-2* extra fully illustrated. HINEBAUCH. "Veterinary Dental Surgery." By T. D Hinebauch, M.S.V.S. For the use of Students, Prac" titioners and Stockmen. Cloth, size 5 1-4x8 256 pages, illustrated '.2 uu HO ABE. (•)««! Manual of Veterinary Therapeutics and Pharmacology." By E. Wallis Hoare. F.K.C.V b Cloth, size 5 1-4x7 1-4, xxvi plus 78u pages 4 75 HOBDAY, (t)" The Castration of Cryptorchid Horses and the Oyariotomy of Troublesome Mares." By Frederick T G. Hobday. F.K.C.V.S. Cloth, sizi 6 d-4 X 8 3-4, It 6 pages, 34 illustrations 1 75 HUNTING. (t) The Art of Horse-shoeiJig. A manual tor Horseshoers. By William Hunting, F R C V S ex-President of the Royal College of Veterinary Sur- geons. One of the most up-to-date, concise books of Its kind in the English language. Cloth, size 6x9 1-4. 126 pages, 96 illustrations 1 00 JENKINS. {*) "Anatomical and Physiological Model of tlie tow." Half hfe size. Composed of superposed plates, colored to nature, showing internal organs muscles, skeleton, etc., mounted on strong boards' . with explanatory text. Size of Model ooened' 10 ft. X 3 ft., closed 3 ft. x IJ ft 12 06 — *' Anatomical and Physiological Model of the Hor«e " Half life size. Size of Model 38 x 41 in... . 12 (Kl These models may also be obtained in smaller sizes together with Models of the Dog, Sheep and JONES n*'The Surgical Anatomy of the Horse." By Jno. T. Share Jones, M.R C.V.S. Part I. To be completed in four parts. Each part— paper, $4 25- cloth, $0.00. Subscriptions for the four parts, pay- able in advance, paper, $15.00; cloth, $17.50. KOBERT. "Practical Toxicology for Physicians and Students " By Professor Dr. Eudolph Robert, Medical Director of Dr. Brehmer's Sanitarium lor Pulmonary Diseases at Goerbersdorf in Silesia (Prus- sia), late Director of the Pharmacological Institute, Dorpat, Kussia Translated and edited by L. H. Frledburg, Ph.D. Authorized Edition. Practical knowledge by means of tables which occupy little space, but show at a glance similarities and differ- ences between poisons of the same group. Also rules for the Spelling and Pronunciation of Chemical Terms, as adopted by the American Association for the Ad- vancement of Science. Cloth, 6 12 x 10, 201 pp.. 2 50 KOCH. "Etiology of Tuberculosis." By Dr. R. Koch. Translated by T. Saure. Cloth, size 6x9 1-4, 97 pages 1 00 LAMBERT. "The «erm Theory of Disease." Bearing upon the health and welfare of man and the domesticated animals. By James Lambert, F.K..C.V.S. Paper, size 5 1-4x8 1-4, 26 pages, illustrated 25 LAW. "Farmers' Teterinary Adviser." A Guide to the Prevention and Treatment of Disease in Domestic Animals. By Prof. James Law. Cloth, size 5 1-4x7 1-2, illustrated 3 00 LIAUTABD. (t)" Animal Castration." A concise and practical Treatise on the Castration of the Domestic Animals. The only work on the subject in the English language. By Alexander Liautard, M.D.,V.S. Having a fine portrait of the author. Tenth edition revised and enlarged. Cloth, size 6 1-4x7 1-2, 165 pages, 45 illustrations 2 00 . . . The most complete and comprehensive work on the subject in English veterinary literature.— American Agri- culturist. — "Cadiot's Exercises in Equine Surgery." Translated by Prof. Bitting and edited by Dr. Liautard. See " Cadiot." — " A Treatise on Surgical Therapeutics of the Domestic Animals." By Prof. Dr. P. J. Cadiot and J. Almy. Translated by JProf. Liautard. See '• Cadiot." — " How to Tell the Age of the Domestic Animal." By Dr. A. Liautard, M.D., V.S. Standard work upon this subject, concise, helpful and containing many illustrations. Cloth, size 5x7 1-2, 35 pages, 42 illustrations 50 — "Lameness of Horses and Diseases of the Locomotory Apparatus." By A. Liautar.l, M.D.,V.S. This work is the result of Dr. Liautard's many years of experi- ence. Cloth, size 5 1-4 X 7 1-2, 314 pages 2 69 LIAUTARD (continued), — (*)** Manual of Operative Veterinary Surg-ery " By A. Liiautard, M.D., V.M. Engaged for years in the work of teaching this special department of veterinary medicine, and having abundant opportunities of realizing the difficulties which the student who earnestly strives to peifect himself in his calling is obliged to encounter, the author formed the deter- mination to facilitate his acquisition of knowledge, and began the accumulation of material by the com- pilation of data and arrangement of memorandum, with the recorded notes of his own experience, the fruit of a long and extended practice and a careful study of the various authorities who have illustrated and organized veterinary literature. Revised edition, with complete index. Cloth, size 6 1-4 x 9, xxx and 803 pages, 563 illustrations 5 qo — "Pellerin's Median Neurotomy in the Treatment of Chronic Tendinitis and Perlostosis of the Fetlocli." Translated by Dr. A. Liautard. See " Pellerin." — "Vade Mecum of Equine Anatomy.'^ By A. Liautard, M.D.V.S. For the use of advanced stuients and veterinary surgeons. Third edition. Cloth, size 5 X 7 1-2, 30 pages and 10 full page illustrations of the arteries 2 00 — Zundel's " The Horse's Foot and Its Diseases." See " Zundel." LONG. "Book of the Pig." Its selection, Breeding, Feeding andManagement. Cloth 4,00 LOWE. (t)" Breeding Racehorses by the Figure System." Compiled by the late C. Bruce Lowe Edited by William Allison, «' The Special Commis- sioner," London Sportsman, Hon. Secretary Sporting League, and Manager of the International Horse Agency and Exchange. With numerous fine illustra- tions of celebrated horses. Cloth, size 8 x 10, 262 pages • 7 5Q LUDLOW. "Science in the Stable"; or How a Horse can be Kept in Perfect Health and be Used Without ^ Shoes, in Harness or under the Saddle. With the Reason Why, Second Edition. By Jacob R. Ludlow M.D. Late Staff Surgeon, U. S. Army. Paper, size 4 1-2x5 3-4, 166 pages .... 50 LUPTON. "Horses: Sound and Unsound," with Law relating to Sales and Warranty. By J Irvine Lupton, F.R.C.V S. Cloth, size fi 3-4 x 7 1-2, 217 pages, 28 illustrations 1 25 M'FADTEAN. (f) " Anatomy of the Horse." Second edition completely revised. A Dissection Guide. By John M'Fadyean, M.B., B.Sc, F.R.S.E. Cloth, size 6x834, 388 paj^es, illustrated 5 50 This book is intended for Veterinary students, -and offers to them in its 48 full-page colored plates, 54 illustrations and excellent text, a valuable and practical aid in the study of Veterinary Anatomy, especially in the dissecting room. — " Comparative Anatomy of the Domesticated Animals." By J. M'Fadyean. Profusely illustrated, and to be issued in two parts. Part I— Osteology, ready. Size 5 1-2x8 1-2, 166 pages, 132 illustrations. Paper, 2 50; cloth 2 75 (Part II in preparation.) MAGNEB. "Standard Horse and Stock Book." By i>. Magner. Comprising over 1,000 pages, illustrated with 1756 engravings. Leather binding 6 (0 MILLS. "How to Keep a Dog in the City.'' By Wesley Mills, M.D., D.V.S. It tells how to choose, manage, house, feed, educate the pup, how to keep him clean and teach him cleanliness. Paper, size 5x7 1-2, 4<) pages 25 MOHLEli. "Handbook of Meat Inspection." By Robert Ostertag, M.D. Translated by Earley Vernon Wilcox, A.M., Ph.D. With an introduction by John R. Mohler, V.M.D., A M. See " Ostertag." MOLLER — DOLLAR. (f) " Kej?ional Veterinary Surgery." See " Dollar." MOSSELMAM-LIEKAUX. *' Manual of Veterinary Microbiology." By Professors Mosselman and Lienaux, Nat. Veterinary College, Cureghem, Belgium. Translated and edited by R. R. Dinwiddle, Professor of Veterinary Science, College of Agriculture, Arkansas State University. Cloth, size 5 12x8, 342 pages, illustrated 2 00 3IOUSSV. n" Diseases of Cattle, Sheep, Goats and Swine." See'' Dollar." NEUMANN. (*)"A Treatise on Parasites and Parasitic Diseases of the Domesticated Animals." A work to which the students of human or veterinary medi- cine, the sanitarian, agriculturist or breeder or rearer of animals, may refer for full information, regarding the external and internal Parasites — vegetable and animal — which attack various species of Domestic Animals. A Treatise by L. G. Neumann, Professor at the National Veterinary School of Toulouse. Translated and edited by Geo. Fleming, C.B., LL.D.. F.R C.V.S. Second edition, revised and edited by James Macqueen, F.R.C.V.S., Professor at the Royal Veterinary College, London. Cloth, size 6 S-i x 10, xvi -1- 698 pages, 365 illustrations 6 75 NOCARD. " The Animal Tubei-culoses, and their Relation to lluniau Tuberculosis." By Ed. Nocard, Prof, ot the Alfort Veterinary College. Translated by H. Scurfield, M.D. Ed., Ph. Ciinib. Cloth, 5x7 1-2, 143 pages.. 1 00 Perhap.s the chief interest to doctors of human meilicine in Professor Nocard's book lies in the demonstration of the small part played by heredity, and the great part played by contagion in the propa- gation of bovine tuberculosis. NUNN. (*)" Veterinary Toxicology." By Joshua A. Nunn, F.R.C.V.S. The study of toxicology is intimately blended with other biological sciences, particularly physiology and chemistry, both of which it on many occasions overlaps. A carefully arranged and com- plete index is given in the front of the volume. Cloth, size Gx 8 3-4, vii + 191 pages 1 75 OSTERTAG. (*)" Handbook of Meat Inspection." By Robert Ostertag, M D. Authorized Translation by Earley Vernon Wilcox, A.M., Ph.D. With an intro- duction by John E. Mohler, V.M.D., A.M. The work is exhaustive and authorative and has at once become the standard authority upon the subject Second edition, i-evised. Cloth, size 6 3-4 x 9 3-4, 920 pages, 260 illustrations and 1 colored plate 7 50 PALLIN. (*) " A Treatise on Epizootic Lyniphang'itis." By • Capt. W. A. Pallin, F.R,O.V.S. In this work the author has endeavored to combine his own experience with that of other writers and .so attempts to give a clear and complete account of a subject about which there Ih little at present in English veterinary litera- ture. Cloth, size 5 3-4 x 8 1-2, 90 pages, with 17 fine full page illustrations 1 25 PEGLER. " Uoat Keeping for Amateurs." Paper, 5x7|, 77 pages, illustrated 5o PELLERim "Median Neurotomy in the Treatment of Chronic Tendinitis and Peribstosis of the Fetlock." By C. Pellerin, late repetitor of Clinic and Surgery to the Alfort Veterinary School. Translated, with Addi- tional Facts Relating to It, by Prof. A. Liautard, M.D., V.M. Having rendered good results when performed by himself, the author believes the operation, which consists in dividing the cubito-plantar nerve and in excising a portion of the peripherical end, the means of improving the conditions, and consequently the values of many apparently doomed animals. Agricul- ture in particular will be benefited. The work is divi(lei92-93. Pamphlet 25 REYNOLDS. "An Essay on the Breeding and manage- ment of Drauglit Horses." By R. y. Reynolds, M.R.C.V.S. Cloth, size 5 1-2x8 3 4, lo4 pages. .1 4U ROBERGE. "The Foot of the Horse," or Lameness and all Diseases of the Feet traced to an Unbalanced Foot Bone, prevented or cured by balancing the foot. By David Roberge. Cloth, size 6x9 1-4, 308 pages, H I ustrated " 6 00 SESSIONS. (*)" Cattle Tuberculosis," a Practical Guide to the Agriculturist and Inspector. Bv Harold Sessions, F.R,C. V.S., etc. Second edition. Size 5x7 1-4, vi + 120 pages 1 00 The subject can be understood by those who have to deal pd,rticularly with it, yet who, perhaps, have not had the necessary training to appreciate technical phraseology. SEWELIj. "The Examination of Horses as to Sound- ness and Selection as to Purchase." By Edward Sewell. M. R.C. V.S. Paper, size 51-2x8 1-2, 86 pages, illustrated with 8 plates in color 1 50 It is a great advantage to the business man to know something of the elements of law, and nobody ought either to buy or own a horse who does not know something about the animal. That sompthiug this book gives, and gives in a thoroughly excellent way SMITH. (•)" A Manual of Veterinary Physiology." By Vet. Capt. F. Smith, C.M.S , M R.C.V S., Examiner in Physiology, Royal College of Veterinary Surgeons, author of " A Manual of Veterinary Hygiene." A completely revised and enlarged edition just pub- lished. Cloth, 6x8 3-4, 720 pp, 102 illust'ns 4 25 The whole book has been carefully revised and brought up to date. All the important advances of the last few years have been embodied. The chapter on the nervous system has been specially revised by Prof. Sherrington, whose remarkable work on the "spinal dog " has been introduced. A special point is made of the bearing of physiology on pathology, and the utilization of physiology to the better understanding of every-day pi'actice. The book is written by a veterin- ary surgeon for veterinary practitioners and students, and is the only work in the English language which can claim to be purely veterinary. — (*)" Manual of Veterinary Hygiene." Third edition rpvised. Cloth, size 5 1-4x7 1-2, xx -f 1036 pages, with 255 illustrations 4 75 Recognizing the rapid advance and extended field of the subject since the previous issue, the author has entirely re-written the work and enlarged its scope, whieh is brought thoroughly up to date. Con- tains over 500 more pages than the second edition. STBANGEWAT. (f)" Veterinary Anatomy." Edited by I. Vaughan, F.L.S., M R.G V.S. New edition revised. Cloth, size 6 1-4x9 1-2, 625 pages, 224 illus 5 00 SUSSDORF. "Six Large Colored Wall Diagrams." By Prof. Sussdorf, M.U. (of Gottingeii). Text translated by Prof. W. Owen Williams, of the New Veterinary College, Edinburgh. Size, 44 inches by 30 inches. 1.— Horse. 4.— Ox. 2. - Mare. 5— Boar and Sow. 3.— Cow. 6.— Dog and Bitch. The above are printed in eight or nine colors. Showing the position of the viscera in the large cavities of the body. Price, unmounted 1 75 each " mounted on linen, with roller 3 50 " THOMPSON, if) "Elementary Lectures on Veterinary Science." For agricultural student?, farmers and stocli keepers. By Henry Thompson, M. B.C. V.S. , lecturer on Veterinary Science at the Aspatria Agri- cultural College. England. It is complete yet concise and an up-to-date book. Cloth, 397 pp., 51 illus.. 3 75 VAN MATER, "A Text Book of Veterinary Oph- thalmology." By George G. Van Mater, M.D., D.V.S., Professor of Ophthalmology in the American Veterinary College ; Oculist and Aurist to St. Martha's Sanitarium and Dispensary; Consulting Eye and Ear Surgeon to the Twenty-sixth Ward Di.spensary ; Eye and Ear Surgeon, Brooklyn Eastern District Dispen- sary, etc. Illustrated by one chromo lithograph plate and 71 engravings. Cloth, 6x9 1-4, 151 pages.. .3 00 . . . We intend to adopt this valuable work as a text book.— E. J. Creely, D.V.S., Dean of the San Francisco Veterinary College. VETERINARY DIAGRAMS in Tabular Form. Size, 28| in. x 2'2 inches. Price per set of five. . . 4 00 Mounted and folded in case 7 CO Mounted on roller and varnished .10 00 No. 1. "The External Form and Elementary Ana- tomy of tlie Horse." Eight colored illustrations — 1. External regions ; 2. Skeleton ; 3. Muscles (Superior Layer); 4. Muscles (Deep Layer); 5. Respiratory Ap- paratus ; 6. Digestive Apparatus ; 7. Circulatory Ap- paratus : 8. Nerve Apparatus ; with description 1 25 Mounted on roller and varnished 2 25 No. 2. " The Age of Domestic Animals." Forty-two figures illustrating the structure of the teeth, indicat- ing the Age of the Horse, Ox, Sheep, and Dog, with full description 75 Mounted on roller and varnished 2 00 ^^■■ilB VETERINARY DIAGRAMS fcontinued). No. 3. "The Unsoundness and Defects of the Horse." Fifty figures illussLniting — 1. The Defecte of Confor- mation ; 2. Defects of Position ; 3. Infirmities or Signs of Disease ; 4. Unsoundnesses ; 5. Defects of the Foot ; with full description 75 Mounted on roller and varnished 2 00 No. 4. "The Shoeing of the Horse, Mule and Ox." Fifty figures descriptive of the Anatomy and Physio- logy of the Foot and of Horse-shoeing 75 Mounted on roller and varnished 2 00 No. 5. "The Elementary Anatomy, Points, and But- cher's Joints of the Ox." Ten colored illustrations — 1. Skeleton; 2. Nervous System; 3. Digestive System (Right Side) ; 4. Respiratory System ; 5. Points of a Fat Ox ; 6. Muscular System ; 7. Vascular System ; 8. Digestive System (Left Side) ; 9. Butcher's Sections of a Calf ; 10. Butcher's Sections of an Ox ; with full d esoription ...1 25 Mounted on roller and varnished 2 25 If ALLEY. "A Practical Guide to Meat Inspection," By Thomas Walley, M.R.C.V.S., late principal of the Edinburgh Royal (Dick) Veterinary College; Pro- fessor of Veterinary Medicine and Surgery, etc. Fourth Edition, thoroughly revised and enlarged hy Stewart Stockman, M.R.C.V.S., Professor of Pathology, Lecturer on Hygiene and Meat Inspection at Dick Veterinary College, Edinburgh. Cloth, size 5 1-2 5 8 1-4, with 45 colored illus., 295 pages 3 00 An experience of over 30 years in his profession and a long official connection (some sixteen years) with Edinburgh Abattoirs have enabled the author to gather a large store of information on the subject, which he has embodied in his book. While Dr. Stockman is indeed indebted to the old for much useful information, this up-to- date work will hardly be recognized as the old " Walley's Meat Inspection." iriLCOX. (*)*' Handbook of Meat Inspection." By Robert Ostel-tag, M.D. See " Ostertag." IFILLIAMS. "Principles and Practice of Veterinarj Medicine." Author's edition, entirely revised and illu'jf rated with numerous plain and colored plates. Bv W. Williams, M.R.G.V.S. Cloth, size 5 3-4x8 3-4, 865 pages 7 50 — " Principles and Practice of Veterinary Surgery." Author's edition, entirely revised and illustrated with numerous plain and colored plates. By W Williams, M.R.G.V.S. Cloth, size 6 1-2x9 1-4, 7.% pages 7 50 THE MOST COMPLETE, PROGRESSIVE AND SCIENTIFIC BOOK ON THE SUBJECT IN THE ENGLISH LANGUAGE (•) WINSL O IF. "Veterinary Materia Medica and Tlierapeu- tics." By Kenelm Winslow. B.A.S., M.D.V., M.D., (Harv.) ; foimeily Assistant Profe.ssor of Therapeutics in the Veterinary School of Harvard University ; Fellow of tite Massachusetts Medical Society ; Surgeon to the Newton Hospital, etc. Fifth Edition, Revised and Enlarged Cloth, size 6 1-4 x 9 1-4, x + 804 pages 6 00 In accordance with the hitherto expressed desire of the author and publishers to keep this work at its highest point of efficiency, it has been deemed incumbent upon them to again present a new and revised edition— the fourth edition of 1906 being exhausted. In the present revision the most notable feature is the substitution of a section on Condensed Treatment of Diseases of the Domestic Animals for the Index of Diseases and Remedial Measures, at the end of the book. In the preparation of this matter, very considerable time and pains have been taken to render this section a reflection and epi- tome of all that is most modern and progressive in veterinary thera- peutics. Special indications for treatment, including drugs and therapeutic agents othei- than drugs, in the different phases and stages of all the important diseases of the domestic animals are to be found. These dis- eases embrace not only medical and surgical disorders, but those of the EYK, SKIN and EAR. If the attempt has been in any degree successful, this new edition to the book should prove one of its most valuable features both to practitioners and students. Moreover, many changes have been made in the text in consonance with recent ad\'ance8 in our knowledge of the action of drugs. WYMAN. (*)" Bovine Obstetrics." By M. G. De Bruin. Translated by W. E. A. Wyman, M.D.V.,V.S. See also " De Bruin." — (*)" Catechism of the Principles of Veterinary Surgery." Bv W. E. A. Wyman, M.D.V.,V.S. Cloth, size 6x9, 321 pages 3 50 Concerning this new tvork attention is called to tlie following Iioints: 1.— It discusses the sub.iect upon the basis of veterinary investigations. 2.— It does away with works on human pathology, histology, etc. 3.— It explains each question thoroughly both from a scientific as well as a practical point of view. 4.— It is writen by one knowing the needs of the student. 5.— It" deals exhaustively with a chapter on tumors, heretofore utterly neglected in veterinary pathology. 6.— The only work in English specializing the subject. 7.— The only work thoroughly taking into consideration American as well as European investigations. 8.— Offering practical hints which have not appeared in print, the result of large city and country practice. WYMAN (Continued) — it/' The Clinical Diagnosis of Lameness in the Horse." By W. E. A. Wynian, D.V.S., formerly Professor of Veterinary Science, Clemson A. & M. College, and Veterinarian to the South Carolina Experiment Station. Cloth, size 6x9 1-2, 182 pp., 32 illus. . . .2 50 — (+)«*Tibio-peroneal Neurectomy for the Belief of Spavin Lameness." By W. E. A. Wyman, M.D.V., V.S. Boards, size 6 x 9, 30 pages, illustrated 50 Anyone wanting to perform this operation should procure this little treatise ; he will find it of considerable help.— The Veterinary Journal. ZUILL. "Typhoid Fever; or Contagious Inflaenia in the Horse." By Prof. W. L. Zuill, M.D.,D.V.S. Pamphlet, size 6x9 1-4, 29 pages 25 ZUNDEL. "The Horse's Foot and Its Diseases." By A. Zundel, Principal Veterinarian of Alsace Lorraine. Translated by Dr. A. Liautard, V.S. Cloth, size 5x7 3-4, 248 pages, illustrated 2 00 Any book sent prepaid for the price WILLIAM R. JENKINS CO. 851 and 853 Sixth Avenue, NEW YORK. DEC IS i907