IRLF sr SB bST 3flM sit, /9O/ u IA. UNIVERSITY FARM •H! In Connection with Pasteurization ..A.. Qo/rvnereial Starter Is a necessity in order to produce in your butter the Highest Flavor, Uniformity and Keeping Quality. Ctir, Haira's Lactic Ferment CHR.HANSENS DANISH t LACTIC FERMENT Being a dry powder, preservable and handy to use, is sold by all dealers in dairy supplies. No contract required. Buy three packages at a time, so as to always have some on hand when you wish to make a new Starter. CHR. HANSEN'S Danish Dairy Preparations — ATIE THE — LEADERS IN DAIRY SUPPLIES. Rennet Extract and Cheese Color FOR FACTORY USE. RENNET TABLETS AND CHEESE COLOR TABLETS for Cheese making on the farm. )ani9b Butter Color, T?heeprSt.in e^ COLUMBIAN BUTTER COLOR, jg> ^ The strongest made. The Marschall Rennet Test, Simplicity Itself. Ask your dealer in supplies for the genuine Chr. Hansen Prepara- tions, and accept no other "Just as Good." for Descriptive Circular. Chr. Hanjten'j; Laboratory, 13 O7. Little Falls. A- ^- pfi$TEURIZflTIOn fli)D MILK PRESERVflTIOI); With a Chapter on Chy MilK_ Supply. AJVD EJVLA'RGE-D E,*DITIOJV. •REVISED \7T TO -DATE. FIFTY CENTS — PUBLISHED BY M O N R A WINNETKA, ILL. UNIV. FARM L. Pasteur in his Laboratory, LOUIS PASTEUR. Born Dec. 27, 1822, this son of a tanner early showed his extraordinary talent, and it' I was to attempt only to enumer- ate the results of his life's work, it would take more space than this pamphlet. Nevertheless I cannot publish a treatise on Pasteurizing without hinting at some of the benefits which the farmers have derived from this great man's work. He is the first one who studied this world of bacteria, or, as he called it, "infinite little" in a systematic manner. Thus he proved how fermentations such as in beer, wine and milk are due to living organisms and that different bodies are acted upon by different ferments. He also showed how most — if not all — epidemic or infec- tious diseases are due to these little fellows and that when once properly known the remedy for the disease may be found. Thus, he saved millions of dollars to the silk worm growers in southern Europe and to the sheep farmers of Australia. The manufacturers of vinegar learned from him that the true vinegar ferment is a little fungus. The wine growers learned that by heating their light wines to 140° and cooling them again, they could preserve them much longer. The brewers received the hint that it was possible to make a uniform good beer, which would keep well, by the same pro- cess of heating and cooling (pasteurization) and the use of a pure culture yeast. All these hints, even if they have not been developed practically by Pasteur, have saved millions of dollars to the farmers. Though Pasteur never took up the milk studies, he is said to have remarked to an English scientist with a sigh: "Ah! there is a rich field indeed for investigations." Nevertheless the useful investigations of milk and its fer- 19865L ments made by other scientists such as Storch, Grotenfeldt, Weigman, Jensen, Freudenreich, Kramer, Adamets, Hueppe, Graeff, Duclaux, Conn, Kussell and others, are all more or less excited by Pasteur's original work. Hence I am correct in saying that if dairy farmers will only apply the lessons given by these men practically, Pasteur will also have been the means of saving them millions of dol- lars. But all this may be said to refer only to dollars and cents, when I think of the human life which this man's work has saved, when I think of the human sufferings which he has alle- viated, then I lay down my pen, no words of mine can express the gratitude which we all owe him. Louis Pasteur died Sept. 28, 1895. INTRODUCTION. The following treatise on pasteurization must not be taken as an endorsement of the general introduction of the systom, far from it: — While conditions often exist which make pasteurizing highly profitable, it is much better if we can eliminate these conditions, — in short, prevention is better than cure. However, we must take the conditions as we find them, and it is far better to pasteurize the milk than to use any of the different preservatives if it is desired to keep the milk sweet longer than is possible by simple cleanliness and ice. Chemical preservatives of whatsoever name and however harmless for preserving other foods, should never be used in milk, as the latter may be given to infants, while the other foods are chiefly used by adults. It seems to me that even if strict prohibition laws are not enforced, every milk producer, every milk dealer ought to have enough conscience to prevent them from using a preservative which may make them guilty of manslaughter. Nor is there any excuse for using chemical preservatives, as pasteurization will do all that they can do, and more. It is well, however, to understand clearly that pasteuriza- tion should not be confused with sterilization. The latter, to be perfect, involves the heating of the milk to such a high de gree (240° to 250°) that it practically destroys it for com- mercial purposes, and even where a somewhat lower tempera- ture is used, (212° to 215°) there is sufficient boiled flavor to make it more or less unpopular. Nor should the simple heat- ing of the milk without cooling be termed pasteurization, which requires both heating and immediate cooling. Meanwhile I shall show the different purposes for which pasteurization may be utilized, and describe many of the de- vices proposed and used. It is my pleasant duty to acknowledge the use of Dr. H. Weigman's excellent little book on this subject "Milch con- 6 servirung," the works of Prof. Duclaux, Freudenreich and Leze , "Milch Zeitung," the Wisconsin and Royal Danish Experiment Station reports and the latest complete work on dairying by Dr. F. Stohmann. Since publishing the first edition, the changes made in the pasteurizing heaters have been so many that several of those illustrated have become obsolete; but, while I have left out several, it seemed to me that the development is best shown by retaining many of them even at the risk of overloading the pamphlet with illustrations. Although the chapter on City Milk has been increased, this subject cannot be done justice in so small a space, and I therefore confine myself to giving a few hints. If any one feel need of more information as to apparatus, it will pay them to send for the catalogues of the various dealers in Dairy and Milk supplies; many of them contain much informa- tion of value. J. H. MONRAD. Winnetka, Illinois, July, 1901. CHAPTER I. MILK AND ITS PRESERVATION. Milk as it comes from a liealtliy cow fed on pure food is abso- lutely pure and sterile, that is, if we could secure it without ad- mission of air in a sterilized bottle, it would keep — if not for ever — for a very long time indeed. Practically this is of course impossible, and thousands of germs (bacteria) float in the dust laden air, adhere to the udder, the flanks of the cow, the hands and the clothing of the milker. Even supposing that the utmost precaution is taken, that the cows are carded and brushed, that the udder, and the hands of the milker are washed, that the barn is thoroughly ven- tilated just before milking, even then remains the favorable breeding place for bacteria, the end of the milk duct in the teats of the cow where they find the best temperature and the best nutrition in the few drops of milk which remain from the previous milking. But it must not be supposed that all these bacteria are undesirable, some of them do no harm, and some of them are useful, not only in the manufacture of cheese and butter but also in aiding us to digest the milk. This explains why there is a difference of opinion among physicians as to the desirability of giving infants pasteurized or sterilized milk. I am therefore of the opinion that wherever we are sure of getting milk from a healthy cow under veterinary inspec- tion and with the above mentioned safeguards, as well as the additional one of using only sterilized vessels, or at least those which have been exposed to steam or boiling water for 10 or 15 minutes, we have done all that can be expected even in this "antiseptic'' age. But, when we come to the practical task of supplying 8 large cities like Chicago and New York with milk at a reason- able price, we meet the difficulty of an effective control. In these cases I do not hesitate to recommend pasteurization for two reasons. (1). It will, without perceptibly changing the taste and digestibility, kill a great many if not all bacteria. (2) It will enable the milk producer and dealer, to preserve the milk sweet for oG or 48 hours longer without fear of com- mitting infanticide with chemical preservatives. In order, however, to get the full benefit of pasteurization it should be done as quickly after milking as possible and the before-mentioned precautions in the shape of the utmost clean- liness must not be neglected. CHEMICAL PRESERVATIVES. The usual precaution taken by honest milk shippers, is to cool the milk before hauling it to the railroad, and where this is done property and the cans kept clean, the dealers in the city manage by a liberal use of ice to sell most of it before souring. But the eloquence of the agents for preservatives as well as the inherent laziness of human nature, which said agents know how to "work," has lately dulled the sense of responsi- bility in the shippers and induced them to use these preserva- tives extensively. Their use is made illegal in most civilized countries, En- gland excepted, where I find not less than 10 different (?) kinds advertised in the dairy papers for 1895 under the follow- ing names "Semper Dulcis," "Arcticanus," "Glacialine," "Sal Preservare," "R. J. J. & B. Preservative," "Preservitas," "Crystaline," "Periodate," "Tomlinson's Preservative" and 1 )uncan's Preservative. Add to this, sundry American fancy names, such as "Pre- servaline," "Milk Sweet," "Iceliene," "Freezine," "Forma- line," etc., and it may be imagined to what extent the public- is being imposed upon by the milk dealers who on their side are being imposed upon by the manufacturers who charge from two to ten prices for a fancy name ! Thus so-called "Milk Regenerene" was offered for sale in London in 1884 at 65c per pound, and it was claimed to re- store the original taste and smell to sour milk. Dr. P. Vieth found it to be 1 part bicarbonate of soda and 2 parts of sugar, worth, at most, only 1) cents! 9 1 shall not enter a discussion on their comparative value, be they composed of Bicarbonate of soda, Borax, Boracic acid, Salicylic acid or the latest by "Effront" Hydrofluoric acid, Fluorites or Formaldehyde. No honest man should use either of them in the milk. PRESERVING BY COOLING. This has, as before said, been used more or less — gen- erally less — by all milk producers, and, if properly done, is' very effective. Most of the bacteria do not develop at a low temperature, which, however, does not kill them. It has been demonstrated by "Cnopf" and "Esche- rich " that they multiply in milk at 90° Fah. twenty-three times in 2 hours while at 54° they only multiply four times in the same time and while in four hours at 90° 215 times, they only multiply S times at 54°. To show how enormous the increase is at the favorable temperature (90°) it is enough to say that in 6 hours they multi- ply 3800 times. Just think of it! for every one of these little germs, hundreds of which may ride on a speck of dust floating in the air, or left in the seam of the milk can, there will be 3800 if the milk is left for six hours at 90° ! If the milk is kept close to the freezing point the increase is hardly perceptible. Ice should thus be the basis for all honest and healthy milk sup- plies and the idea of freezing the milk into solid blocks lies near. This has been done in Paris (France) by "G. B. Guerin." The milk was filled in vessels which when frozen by a refrig- erator machine, were insulated for transportation. Frozen milk has been used for years on board ocean steamers. As it takes quite a while to freeze milk solid, there is a drawback in its creaming during the process, so that the "block'7 consists of a very poor layer at the bottom with one of cream on top and a very concentrated not frozen milk in the funnel-shaped indenture in the middle of the block. Thus a thorough mixing after melting is made rather difficult. This phenomenon has even been suggested for the con- densing of milk instead of heat, which will be mentioned later on. The Casse System (patented about 1894) is based upon the 10 fact that milk partly frozen or in which lumps of frozen milk are kept floating, will keep almost indefinitely so long as there is any ice left, and will come out, when thawed, as fresh as new milk, ready to be distributed as wanted. A part of the new milk, say J to -J is frozen solid by means of ice machines as used in the manufacture of artificial water-ice, as soon as possible after milking, and is then damped into the rest of the milk. The cans may then be transported any dis- tance in well insulated cars, and, on arrival at the city milk depot, placed in some insulated store room — care being taken that ice remains in the milk until it is to be distributed. When the milk is to be delivered, it is dumped, ice and all, into a melting tank, where the remaining ice is quickly thawed and the whole is thoroughly mixed, when it is ready for distribu- tion in the same fresh condition as it was in at the time when it was frozen. If desirable, the milk may be pasteurized before it is frozen, and it may be filtered or run through the separ- ator to remove the impurities, or subjected to any other suit- able treatment. The main thing is that, properly handled, ac- cording to the Casse system, it will come out when thawed exactly as it was when frozen, and that therefore the difficul- ties of transportation at any distance, in any climate and of shortage or surplus, have been completely conquered. An- other important point in favor of this system is the fact at first thought quite surprising, that, as long as there is ice left floating in the milk, the cream will not rise, but remains naturally distributed as in fresh milk, and that therefore no difficulty arises from that source as would be the case if the milk were kept simply in cans surrounded with ice. The system, I understand, is used in Denmark, England, Belgium, and in Germany, where Wilhelm Helm, of Berlin, de- scribes his plan in 1900 in a German health magazine, a plan which is virtually Casse's system, and operated under that patent. The milk is taken good care of by the farmer and cooled before hauling to the factory. Here it is tested for acidity, weighed and run through the pasteurizer, from which it is pumped on a large cylindrical cooler, the upper half of which is cooled by water, the lower by brine, so that the milk arrives in the cans virtually at 32° Fah. The cans are then run down into the half cellar (which is cooled by the refriger- ator machine) and stacked in a solid square. When shipped a piece of milk ice, frozen in special forms in a freezing tank, 11 is added to each can and thus preserved in transit to the city depot. This system is in actual operation at Rheinsberger. The cans used are illustrated in Fig. 1. As will be seen the lower rim is wide enough to al- low the handles and neck of the lower can to tele- scope into the upper one and thus they may be stacked solidly. The advantages claimed are that a great saving of space is obtained and that owing to being packed vir- tually solid, there is little chance of change in tem- perature, if the outside is protected with straw mats. All of which is true, but he does not discuss the extra expense (per quart) of these cans, nor the increased difficulty in keeping them clean, both of which objections are evident. PRESERVING IN VACUUM. In I/Industrie Latiere May 10, 1891, M. C. Nourry ex- presses his belief in this system, and though I do not share this belief, it may be of interest to put it on record here. Figs. 2 and 3 represent the proposed can, A is the body of the can preferably enamelled, c is the piston screw, which is Fig. 3. turned by the handle D. B is the piston head with valve G opening up and F opening downwards. H is the opening in the cover and j a slide which slides in a groove on the lower side of the cover. Suppose the pistonfread B is at the top «&, the can is full of air. By screwing the pistonhead down to cd the air is ex- pelled through the valve G. The milk is now poured in by the opening H so as to fill the whole can and the opening H as well. This drives all (or nearly all) the air out and the slide J is closed. The pistonhead is then screwed up to «?>, letting the niilk through by F into the space c d e f where it is free from air. When the niilk is needed, a few turns on piston will press some through G and it is poured out by H. The apparatus is cleaned by unscrewing the cover at v and the inside of the can as well as the pistonhead may be made of glass! Granted that this process will do all that it is claimed, granted it will prevent the cream from rising, granted that the anaerobic microbes cannot develop unless their aerobic cousins have prepared the way for them and granted that the latter cannot live without air, granted all this, my readers will agree with me that the cost of such cans would preclude their use. PRESERVING MILK UNDER PRESSURE. Experiments on this line were made and reported by Prof. B. H. Kite, in Bulletin 58, 1899, of West Virginia Experiment Station. A 100-ton hydraulic press was used and in this the milk enclosed in a lead tube about 1 inch in diameter and 5 inches long was submitted to a pressure in a solid steel cylin- der of from 5 to 30 tons for one to three weeks. The best results seemed to be obtained with a pressure of from ten to fifteen tons for ten to fourteen days, and the report says: "That the milk could be shipped a five or ten days' journey, there can be little doubt, but the cylinders capable of carrying such pressures would probably weigh more than the milk." Experiments were also made using a pressure of from o to 20 tons and heating the milk to from 140° to 170° Fah. for from five minutes to four hours, and it kept sweet for 19 days. Interesting as these experiments are, it seems to me there 13 is no chance of the system coming into practical use, as the difficulties are too great when the system has to be applied on a commercial basis. PRESERVING BY ELECTRICITY. This, like butter and cheesemaldng by electricity, has been talked about, but while experiments seem to have proved that electricity may, to a certain extent, paralyze microbes, nothing practical has been evolved as yet, as far as I know. PRESERVING BY HEAT. It has been shown how the bacteria germs develop best at about blood heat and how their development is reduced all the more, the colder they are kept, — but excessive heat has a. better effect — it kills them. This has been known for ages and the preservation of milk and cream by boiling is a com- mon precaution among housekeepers. Yet, unless the milk is cooled down and kept cool, the effect is only to keep it sweet for 12 to 24 hours longer and the boiled taste, to which so many people object, prevents its general use. This taste is much more pronounced in milk heated in open vessels than in milk sterilized under steam pressure in the modern apparatus, and yet there is the same objection of its being made less digestible by the coagulation of the albumen. Compare the digestibility of a soft boiled and a hard boiled egg or that of a raw and boiled oyster. In creameries the heating of the skim milk to nearly boil- ing point (195°) without cooling, is often miscalled pasteuriza- tion, but it has been proved by actual experiments in Den- mark that though pasteurization may be better if the milk is cooled properly and the patrons' cans are cleaned before fill- ing, the expense of cooling is too great, and hence, it is far better simply to heat the milk to such a degree that it will kill the bacteria in the little milk left in the unwashed cans. Here also have the creamery men been satisfied with heating, though I fear that in too many cases, the temperature is too low to do effective work. PRESERVATION OF MILK BY CONDENSING. Although the idea was first suggested in the beginning of the 19th century by the Frenchman Appert, it was not until 14 in second half of that century that the problem was solved in a satisfactory manner. All the first atempts were simply to add 6 to 12 per cent sugar and evaporate in open pans often at temperature of 185° to 195°. In 1835 William New- ton took a patent for an unknown foreigner whereby 1 to 7 per cent sugar was added and then condensed in vacuum, and thus the first step was taken in advance. In America, E. N. Horsford took the lead and his assistant, Dalson, started a factory with Blatchford and Harris,near New York about 1850. In 1.85G Blatchford used a vacuum pan and in the same year Gail Borden took a patent on using the vacuum pan for condensing milk without the addition of sugar, but it did not keep well and later he added sugar and canned it, thus making his name known all over the world, and indeed it was he who first started the business on a large scale and practical scale, and for years ".Gail Borden" and "Anglo Swiss" (started 1865) brand virtually had a monopoly. Lately several large and many small factories have gained a fair reputation and are working on a paying basis. About 1884 the Highland (111.) factory started success- fully to make and can unsweetened condensed milk and tried to market it as such with but scant success until the "happy thought" (?) occurred to label it "Evaporated Cream," and at present nearly all the factories put it on the market under this false label. Illinois State Food Commission has taken the first step to prevent this fraud by demanding the ex- planatory words "an unsweetened condensed milk" on the front part of the label, but the use of the word cream should be prohibited. I regret to say that other frauds are being committed. Thus by condensing skim milk, which is sold without labeling it as such, — and this is also used to the harm of the dairymen by adulterating cream, giving it a body which fools ignorant people. Just to give those who have not seen a vacuum pan an idea of it, I illustrate one made by Gaulin & Cie, of Paris. France, in Fig. 4. There are three sizes. One for 500 Ibs., price, $200; one for 1,000 Ibs., $250, and one for 2,000 Ibs., |325 f. o. b., Paris. The milk is first mixed in a receiving vat, then passed over a pasteurizing heater into the tank, where 10 to 12 per 15 cent sugar is added, and it is then pumped into the vacuum pan. Fig. 4. To the left is shown the tank from which the milk is drawn into the pan and to the right is the condenser where a spray of cold wrater condenses the stream and thus helps the air pump in creating the vacuum. If the boiled taste were not objectionable, it seems to me that condensed milk without addition of sugar, would be a more rational way of solving the milk supply of large cities,but though this has been' attempted in several large places, it can not be said to have become very popular, and it is chiefly used, as before said, for adulterating cream. Condensing milk with addition of sugar has been, and, I believe, will be the favorite method of preserving milk for ship's use and in mining camps, where the transportation of 75 per cent water is quite an item. CONDENSING WITHOUT VACUUM, F. Streckeisen (Switzerland) has introduced a cheap sys- tem of milk condensing for farmers. It consists of a pan (resting on four columns) in which rotate slowly one or two cylinders which are heated by steam. Fig. 5. The shafts are hollow and provided with 39 hollow heating rings, about 18 inches in diameter, into which the steain escapes through holes in the shaft. These rings are fitted closely to the shaft and held firmly by two nuts and may thus easily be removed for clean- ing. The steam pipe runs through the shaft and does not rotate, but has 39 openings corresponding with those of the shaft and the rings. The con- densed water escapes through the shaft into the columns. Fig. s. The milk is picked up by the revolv- ing drum and spread in a thin film whereby evaporation is promoted and as soon as the condensa- tion is finished, the steam is turned off and cold water run into the drum in order to cool the milk. The condensing ca- pacity is said to be 400 fbs., 800 rbs. and 1,200 Ibs. respectively for the three sizes, figuring on a condensation to one-third, and the price quoted is $400, $700 and $960 in Utzenstorf, Switzerland. This seems rather a step backward, as the condensing in vacuum has so many advantages. PRESERVING IN POWDER FORM. From evaporating to one-quarter volume, the idea lay near to evaporate to powder form, and it has been tried and announced again and again. Thus lately I had a sample of milk powder sent me from Denmark, made by a process patented in Denmark about 1899, by Ole B. Wimmer, but it dissolved very slowly and had a strong cooked flavor. I pre- sume they are still working at it. In February, 1900, Messrs. Bechel & Kittel patented a process for evaporating milk in vacuum at 104° and then dry- ing it in ovens at the same temperature after which it is pow- dered. By adding bicarbonate of sodium it is said to be made more soluble in water. If the problem of getting a quick and satisfactory solu- tion of the powder in water is solved, then there are many attractions in this system. IT <'OXI)KXSIX<; r,Y FREEXlXti. What the new system of condensing milk by freezing may turn out to be, I cannot foresee, but unless such milk is kept frozen or nearly so, it seems that its keeping quality must be very problematic. It is claimed (Mclntyre) that by freezing the milk in shal- low metal pans it is possible to secure a thin layer of pure ice on top and by breaking this up the whole mass of milk is con- verted into a mixture of ice crystals and condensed milk. This mixture is put into a large separator like those used in sugar factories and the condensed milk strained from the crystals by centrifugal force. The remaining crystals are said to analyze 0.2 of solids. This system would have the advantage of a natural flavor, but I fear it will not prove practical, nor has anything more been heard of it since first announced some six or seven years ago. PRESERVING BY PASTEURIZING. While the heating of milk to boiling point, or there about, always gives a boiled flavor, it is possible to reduce this so as to make it barely perceptible by heating only to 150° to 155° Fah. Experiments have shown that if the milk is kept at this temperature for 20 to 30 minutes most of the bacteria will be killed. First of all the lactic acid bacteria will succumb and this is the fellow which generally "loppers" the milk. But other and more dangerous bacteria among those which are most liable to be found, are also killed. Thus did "Bitter" find that 30 minutes at 155° killed the tubercle, the typhoid and the cholera bacillus. But there are also others which require a temperature of 230° and more to destroy — and it is thus evident that a per- fect safeguard is not even obtained by heating to 212° or 215°. And if this is so, it seems to me absurd to attempt to over- come the popular prejudice against the "boiled flavor" when we can secure a safeguard against the most common dangers by heating only to 155° which does not develop that flavor. But it is not only the danger of boiled flavor which de- lays the introduction of pasteurization. The cream does not rise and make as good a showing in the bottles, the cream ap- pears thinner, and hence people are led to believe that they get a poorer milk, a less rich cream. Drs. Russell and Babcock showed (Wisconsin Report, 1896) that this lack of "body" in pasteurized milk was due to a change in the condition of the fat globules, a change strik- ingly illustrated in the illustrations of unpasteurized milk (Fig. 6) and pasteurized milk (Fig. 7), and they found by ex- perimenting that the addition of a compound of sugar and lime would restore the viscosity (the "body") and recommended it - — as it really is — as a harmless remedy. Fig. 6. Fig. 7. They little suspected that they thereby gave unscrupulous milk men a pointer how to increase the "body," that is, the apparent richness of unpasteurized milk and cream. That this has been the result is indicated by a well known supply house advertising : "Viscogen for restoring consistency of pas teurized and separated cream." Meanwhile Dr. Theobald Smith in 1898 reopened the ques- tion as to the exact temperature and the time needed to kill the tubercle bacillus and in Wisconsin Report of 1899 Profs. Russell and Farrington tell us that they have confirmed Dr. Smith's experiments that heating milk to 140° for 15 to 30 minutes does not change the "body" of the milk, does not affect the rising of the cream, as does heating to 150° or above. They also found that there was practically no difference in the keeping quality of milk heated to 140° for fifteen min- utes and that heated to 150° for the same time, nor did the bacteriological examination indicate any advantage in using the higher temperature alivays provided that milk is agitated while being heated as otherwise — as in bottles — a film or skin which protects the bacteria, forms on top of the milk, so that even heating it at 140° for one hour will not be satisfactory. 10 This is a rather surprising result to those who have fol- lowed the tendency in Europe, which seems rather to be in the direction of demanding higher temperatures. In Den- mark, as for instance, the law demands a temperature from 185 to 190° in the continuous heaters as against the old limit of 165° to 170°. Leaving the scientific questions aside, I con- sider that Drs. Smith, Farriugton and RusselFs work is of the highest practical importance to the city milk suppliers. The unpasteurized milk in these experiments kept for two days, while the pasteurized kept for at least six days. It is thus sure that we can preserve milk by pasteuriza- tion without the before-mentioned drawbacks, yet it is signifi- cant that Dr. Russell in a reply (see further on) to an inquiry, says: "It will necessitate, however, the securing of better class of milk to begin with," and it must also be remembered that the patrons of Madison University creamery have been educated to deliver milk which undoubtedly is above the aver- age quality received at our creameries. The question is then, Will the same results be obtained on milk of a poorer quality? If so, it seems to me this discovery should revolutionize our milk trade. But, w'hile heating to boiling point and even heating to 140° kills most of the bacteria, it does not kill their spores, and hence if the milk is left at a favorable temperature (between 80° and 100°) for any length of time, the germs will develop and the battle commence anew. The milk must therefore be cooled immediately as low down as possible, at least to 50°, and it is of the highest im- portance that this is done quickly. While scientists have and do even now insist on the neces- sity of keeping the milk at the desired temperature for a more or less extended time (according to the temperature) when pasteurizing milk for city supply, I have secured good results as to increasing the keeping quality with the continuous heat- ers where the exposure to the heat is only one or two minutes, and it is a question whether this is not due to the fact that the milk coming from these heaters is cooled so much more suddenly than in the tank heaters. In order to get the latest American scientific opinion on this question, I wrote Drs. Russell, of Wisconsin, and E. N. Eaton, asking their opinion as to the practicability of contin- 20 nous heaters for city milk, and quote from the reply of Dr. Russell: "' * * *We are still working on the subject of pas- teurizing at 140°, as I think for commercial purposes this is very much preferable to the application of a higher tempera- ture where the viscosity of the milk is so reduced. *It icill necessitate, however, the securing of better class of milk to ~beyin with:' * * * "Regarding the question of continuous vs. intermittent pasteurizers, I may say that I have yet to see any device which warranted me in changing my previous opinions in regard to the desirability of continuous pasteurizers for city milk sup- plies. I am aware of the fact that there are a number of continuous pasteurizers upon the market for which more or less extravagant claims are made, but it is a fact that the most energetic of these concerns do not seem to be inclined to submit their apparatus to a strict bacteriological test; they prefer to sell it on the merits of practical demonstrations, as they say. "There is no question that from the standpoint of capacity the field is theirs, and, in fact, their type of machine appeals to the man who pasteurizes milk, but I believe we must main- tain the interests of the consumer as well as the producer of pasteurized milk, and I am not willing to commit myself to any continuous machine which it has been possible for me to test. We have subjected one or two of these to a more or less critical examination and find that they do not come within gun shot of their reputed claims. Of course, I do not say that there are none that may not give proper treatment, but we have tried earnestly to have the manufacturers of these ma- chines send us one for close examination, and they have failed to do so." And from Dr. E. N. Eaton, of Illinois: "# * * As to the efficiency of continuous pasteurization wt know that the tendency of late has been to decrease time and temperature below former standards. Elaborate experiments by microscopical, bacteriological and inoculation methods have shown that a temperature as low as 140° Fah. for 10 minutes especially in closed vessels will destroy pathogenic bacteria, Italics by J. H. Monrad. 21 or at least 'bacillus tuberculosis;' the object and end of pas- teurization. "Continuous pasteurizing machines have been in use some years with good practical results. The more recent ones have been scientifically examined and have given a good account of themselves, culture plates from such milk showing none but spore forming bacteria after a prolonged period of incu- bation. I have cursorily examined milk before and after en- tering continuous pasteurizer and found the latter to keep at least one-.third longer at room temperature; the decomposition after standing being similar to that of normal milk. In this repect the milk differs from milk heated to boiling or so-called sterilized milk. "The performance of the continuous pasteurizer cannot be explained on the ground of the heat being fatal to germ life, as many experiments have shown that a higher temper- ature for a longer time will not destroy all disease germs. "The explanation of the efficiency of the continuous pas- teurizer is very likely due to the extremes in temperature — to the rapidity with which the heat is applied and to the sudden cooling of the milk. When using the old Russell vat pasteurizer I noticed a great improvement in the product when the milk was cooled quickly to 50° Fah. or below. In practical use the milk was cooled to 120 to 100° Fah. in the machine, which could be accomplished in a few minutes and then it was drawn off through pipes conducted through a freezing mixture, bottled and stored in the refrigerator until ready for distribution. The results of this method indicated the ad- vantage, if not necessity of quick cooling, and forecast the success of the continuous pasteurizer, utilizing this principle. "Some of the best germicides possess the property of co- agulating or combining with albumen — such, for example, as mercuric chloride, formaldehyde and heat. Yet other very good antiseptic agents have not this property and must depend for their necrophytic action on a different property. It is rea- sonable to suppose that the physical shock due to the sudden expansion and contraction of tissue would result in the de- struction of the one celled organisms. "Neither the taste nor the creaming of continuous pas- teurized milk will be a bar to its acceptance, as it acts in these respects like normal milk. * * *" Then, again, I find in L'Industrie Latiere, Feb. 23, 1900, M. Galtier quoted as saying: "The result of my investigations is that milk, abundantly inoculated with tubercle germs, is not absolutely sterilized by heating for 6 minutes to 158°, 176° and even 185°, the milk from suspected animals should be boiled for consumption by man or beast." Dr. Stohmann, in his book "Milch and Meiereiproducte," says, page 402: "The killing of the bacteria will ~be promoted through the sudden change of temperature" It seems to me there is a field open for careful experi- ments because pasteurization will hardly become popular on a large scale unless the continuous heaters and coolers may be used under the approval of the scientists. But even if it is desired to keep the milk hot xfor a cer- tain time, it is, as T have before suggested, possible to use a continuous heater and cooler by interposing three storage tanks, each holding one-third of the hourly capacity of the heater and cooler (if 20 minutes is the time) and thereby se- curing the advantage of continuous apparatus and the sud- den chilling of the milk. In Fig. 102, page 99, Mr. A. H. Keid has solved the problem by interposing a sort of D. W. heater as a storage tank. INTERMITTENT 'PASTEURIZATION. Dahl (Norway) proposed to heat the milk inclosed in ves- sels to 158° for 3 hour, then cool to 104° for the same time, then heat again and cool, in all four times. At last heat it to 175° or 212° for half an hour and cool to 55 degrees. This is however neither sterilizing nor pasteurizing and is simply a modification of the intermittent sterilization pro- posed by Tyndall, and though very effective it is very com- plicated and expensive. Large quantities of milk have never- theless been shipped to London from Norway, preserved by this "Dahl" method. The theory is that the comparatively low temperature only kills the bacteria, and by cooling to 104° the germs are given time to develop so as to be killed in the second heating. I have made a few experiments which lead me to believe that if an increased safety and keeping quality is desired the following process may be practical. It is simply a modifica- tion of DahPs and is to heat to 155°. Keep it there for half an hour then cool to 100° and keep it between 90 and 100 for 23 2 or :"} hours, then heat to 155° foi- half an hour and cool to 50°. While no bacteriological examination controlled these experiments I secured a prolonged keeping quality over and above the single heating and cooling of about 12 hours. STERILIZING. Though I consider it absurd to object to the insignificant "boiled flavor" which the best sterilizing apparatus leave in the milk, and though I acknowledge that if pasteurizing is good as a protection against infection and as a means of pres- ervation, sterilizing is certainly better, I write for the great army of practical dairymen, and for these sterilizing with its rather expensive apparatus is of less interest, and hence J confine myself chiefly to pasteurizing and only illustrate a few of the latest sterilizing apparatus used, all of which, however, may be also used for pasteurization. I just mention the apparatus shown at the Columbian Exposition by Popp & Becker, of Berlin, which is advertised in German papers under the name of "S-TERILICON" and for which F. Correll & Co., 182 Nassau street, New York, is agent. Neuhauss Gronwald Oehlmann also showed his apparatus both for bulk and bottle sterilizing and slioweu it in working order. Besides this Dr. Weigman describes one made by Paul Ritter von Hamm. Any one who studies the apparatus described for pasteur- izing can easily adapt or modify some of them for^ sterilizing. But if care is needed for pasteurizing, much more care is required for sterilizing as the object here is not only to kill most of the bad bacteria, but also to preserve the milk not for days or weeks, but for months. I sampled milk sterilized in the "Sterilicon," which was claimed to be six months old and which was perfect. Most of the sterilizers are tanks fitted for a high steam pressure in which the milk is exposed for the desired time in bottles, and the inventive energy has chiefly been directed towards solving the problem of an automatic closing of the bottles in the apparatus when hot. Success has been ob- tained more or less, and I illustrate the simplest and cheapest 24 one in Fig. 8, the Simplex, from an ad- vertisement of The Dairy Supply Co (London). The arrangement for closing* the bottles automatically while in the apparatus is not quite clear, but I con- sider it immaterial, because the system first suggested by Dr. Soxhlet (Germany) introduced in 1891 is the simplest sys- tem of closing sterilized milk bottles. The mouth of the bottle is slightly fun- nel shaped and ground smooth. On this is laid a round sheet of rubber, 4 mil- limeters thick. (See Fig. 9). This rub- ber is held in place by a metal cap open in both ends. (See Fig. 10). When the milk heats the air and steam is free to escape and yet does not throw off the rubber, as it is held by the cap. As soon as the cooling commences the vacuum formed in the bottles holds the rubber tightly to the mouth of the bottle, closing it automatically. The great beauty of this system of sealing is that as soon as any fermentation starts the gases wTill Fig. 8. Fig. 9. Fig. 10. destroy the vacuum and release the stopper, giving notice that something is wrong. Dozens of modifications of this idea have been introduced since then. 25 M In Fig. 11, copied from Stoh- maim's book is shown the ap- paratus designed by Prof. Back- haus (Germany) in which small bottles of J quart are placed. The bottles have a heavy, smooth, slightly conical edge on the neck in which there is a sort of channel. The rubber cover fits tightly at the top, but when expanded by the steam developed in heating it opens up the channel and lets the steam out. When cooling the rubber is drawn closely to the head of the bottle sealing it. The apparatus itself consists of a cast-iron table P on a foot piece with a hollow column B in the center. On this are sev- eral movable circular shelves T. The steam is distributed through holes in the column by the pipe A, and also draws the cold air for cooling. Above this is hung a cupola C, made of copper (counterbalanced by E), which is let down on P and fastened steamtight by screws. The guide K compels the cupola to come in the exact place so as to let down the thermometer M into the cup G, which is tilled with milk. The thermometer D shows the temperature in the cupola, which is also provided with Manometer J, a safety valve H and a blow off cock F. The cock H below the table lets the condensed water off. A somewhat similar apparatus was used by Dr. E. N. Eaton in Minneapolis, where he prepared an imitation of human milk. He heated the milk, after modifying it, to about 212°, then cooled it to 100° and left it for three hours for the germs to develop, then reheated it and cooled the bottles by placing them on a cement floor and spraying them with cold water. Milk thus treated would keep for months. Some objections have been made to the use of rubber stoppers, especially when they are new, they are liable to im- Fig. 11. 26 Figr. 12. part a flavor to the milk. This sup- posed danger is reduced or rather re- moved by the system "Rheiriland" shown in Fig;. 12. It consists of a wide- necked, nearly cylindrical bottle, ground smooth on the upper edge. On this is laid a rubber ring and a thin disk made of tin or aluminum. A spring holds both in position while heating, allowing air to escape, and is removed when the vacuum created by cooling holds the cover tightly. The opening of the bottle is done by simply inserting the point of a knife and letting in air. PRESERVING BY CARBONIC ACID GAS. H. de Lavallee (France) proposes to preserve milk by filling it in a cool reservoir at once after milking and submit it to the action of carbonic acid gas under a pressure of five or six atmospheres for four to five hours; then let the carbonic acid gas escape and treat it with oxygen under pressure of five atmospheres. It is claimed that both aerobic and an- aerobic bacteria are killed by this treatment. The milk is transported in cans with oxygen under a pressure of two at- mospheres. Like so many other systems it is condemned on the face of it— even if effective — on account of the unneces- sary work entailed. CHAPTER II. THE PASTEURIZING HEATER. Continuous Heater. In writing the history of the apparatus which have been and are used practically, I try to mention them in their proper chronological order, but lay more stress on grouping them to- gether according to the principles involved. It must always be remembered that a pasteurizing ap- paratus must consist of a heater and a cooler unless indeed the same apparatus is used for both as in Prof. Russell's, John Boyd's, Potts' and others. HEATER. . In Denmark the first heater used was the one constructed by the late Prof. Fjord for heating the milk for the separa- tors Fig. 13. This con- sists of a strong wooden barrel D in which a tinned copper vessel C is inserted. A stirring ap- paratus K prevents the milk, which enters at M through H, from scorch- ing on the side. Steam is introduced by F if ex- haust and E if direct steam is used. Con- densed water escapes through G. The milk outlet not shown in the illustration, is above tl:e wood. \Yh niilinu- ters back to the front purr where it is elevated through a pipe to the right by the centrifu- gal force of the wings on the drum. The steam enters the jacket through the other pipe. This gave me the idea of con- structing a heater for A. H. Barber & Co., of Chicago, sec- tional cut of which is shown in Fig. 23. It consists of a cast iron base I, in which a turbine flyer f is inserted and driven by steam from pipe fs. It has also pipe T for the exhaust, but this is, as a rule, closed by the damper K, when not less than 1,000 pounds per hour is treated. Fig. 23 is a cross section of the heater where G is a galvanized cylinder riveted to the base and provided with an annular tin gutter H. D is a slightly conical tin drum soldered to a tinned brass or malleable iron bottom with a spindle which fits in the cup C revolved by the turbine flyer f. The drum D is strengthened by a hoop at the top, into which is riveted a cross (r) of four rods which again brace the 1-inch pipe P that acts as . spindle for the drum. The cylinder Fig. 23. G has a flat cover with a cross bar B, which is held in position by two thumb screws m. In the center of this bar is the upper bearing. The milk enters at P through a regulating cup such as used for separators, and is thrown out of four small holes at 34 the bottom of the pipe PP, and fills the space M where any possible dirt collects. It then overflows the ring d and flows in a thin film (shown by the arrows) and is thrown in the gutter H, leaving through the spout with the thermometer L. The exhaust steam from the flyer f goes up through eight holes X X into the cylinder and heats the drum D. In run- ning about 1,000 Ibs. of milk per hour I raised the milk from about 54° to 155° with the exhaust steam alone, but when I ran 1,500 Ibs. an hour I had to use some live steam, which is led through the pipe S under the bottom of the drum. If the steam pressure and milk supply is uniform this apparatus heats it steadily within a variation not to exceed 4° or 5° Fah. A wooden jacket would be advisable to economise steam es- pecially in winter. The condensed steam escapes by K and by two small holes II in the bottom. Fig. 24. While the milk does not get any perceptible "boiled taste," there is, after running 3,000 Ibs. through it, quite a layer of coagulated albumen, which takes some labor to clean off. Yet I would far rather clean that one drum instead of five or six cans, even if the albumen deposit is less there. In Fig. 24 the apparatus is shown as connected with three Baer coolers, I also proposed to utilize the same idea by having the bottom of the drum cast with shovels on, and rotate it by a 35 fhovi JFOI steam jet. By this, application, or by driving it with a gear- ing at the top it is optional whether the milk shall be taken in from the top or through the bottom bearing. The advan- tage of the latter plan is obvious as the heater will act as an elevator at the same time, thus killing two birds with one stone. As the drum is twenty-eight inches deep it will be possible to lift the milk at least two feet from inlet to the outlet of the gutter, and with a higher speed than that used by me, 450 to 500, it may be arranged to elevate to any height. Mr. A. H. Barber (Chicago) later substituted the Hill heater, Fig. 25, where the milk cylinder is kept rotating slowly by the steam jet, which M.^NLCT heats the water. Inside this revolving cylinder is a stationary one which °* reduces the milk space to a very narrow one. The milk enters through a center tube and rises between the two cylin- ders. It is made with an hourly capacity of from 500 Ibs. up to 2,500 Ibs. and sold at from f 35 to |75— the latter, if made of copper, cost |100. Another style is made where the cylinder is Fig. 25. revolved by a rope belt from 15 to 30 revolutions per minute. A cooler on similar principle is also made. Mr. A. B. Reek's (Denmark) heater is shown in Fig. 26. Here the steam heat is applied to the inner drum B, which is revolved by a hollow shaft A with pulleys S and goes through the bearing b fixed on the frame not shown. The steam enters through this shaft and the condensed water is removed by two "skimming" tubes S, to a fixed pipe V. An outer stationary jacket C covers the steam drum, leaving only J inch space between them. 36 The milk enters at T and passes through this half-inch space, being prevented from fol- loAving the revolving drum by some ribs on the outer jacket, and leaves at A. The cleaning is done by lowering the outer jacket, which slides on the pillar K, supporting the ap- paratus. The drum revolves about 170 times per minute, and the milk held in the appar- atus is 30 Ibs. The Miller heater is a modifi- cation of the Hill (Fig. 25), and the Reck (Fig. 26), and seems to be constructed on a good principle, although I have heard varying reports of it, some prais- ing it highly; others making light of the claimed advan- tage. Although Mr. Miller, who lives in Canton, Ohio, did not answer my inquiries, I had the opportunity of seeing it in operation at the progressive milk dealers, Mr. Sidney Wanzer & Sons, Chicago. The plant consists of one heater and two coolers. The heater consists of a wooden tub in which is in- serted a tinned copper cylinder so as to leave a water space. Jn this the water is heated by a steam jet on a similar plan that Barber used so as to get a circulating motion in the heat- ing water. This drum has an annular gutter into which the milk overflows. Inside, a revolving drum leaves the milk, introduced from the bottom, only a half inch space in which to rise while it is being heated from both sides. The inner and revolving drum has a curved ring which covers and over- laps the milk gutter so as to prevent the overflow water from getting in the milk. A steam jet sends hot water into the revolving drum and the overflow is sent over the curved ring into the outer water space. Fig. 26. 37 With the heating water at about 170°, this heater heated milk from 60° to 158° at the rate of 1,600 Ibs. per hour, and, no doubt, might do even a little better. Mr. Wanzer is careful in selecting the milk, and when rinsed while in motion with cold water and later soaked by pouring in a solution of lye, the surface showed no milk scorched on the drums when taken out and cleaned. The center cooler with a half-inch stream of city water (54°) cooled the milk from 158 to 80°, and the brine circula- tion, which on an average was 22° cooled it from 80 to 50°. The coolers are made with the outer cylinder of galvanized iron instead of wood and the inner cylinder was soldered to this so that the exact system of circulation could not be seen, but the revolving drum was made like the heating drum. The cooling capacity of the brine cooler could be increased if the revolving drum was filled with crushed ice instead of water. Take it altogether, while the manufacturers exaggerate in their circular, this is about as nice a heater of the hot water kind that there is on this market, and it is fairly well made, barring a few points which may easily be improved. The price is too high by about fifty per cent. As to the coolers, I fail to see why we should fool with revolving drums, etc., when we have so many excellent surface coolers where the milk is aerated much better. The operator has to watch the steam valves all the time just as with the Monrad centrifugal heater, or indeed most all of them. This might be improved by having a small supply tank with a ballcock so as to have uniform pressure on the milk and the steam pressure might also be made more uniform. The only original feature in this apparatus is the fine wire soldered spirally on the outside of the revolving drum, This is claimed to give additional motion to the milk and to increase the capacity, a claim which I cannot understand. There is surely motion enough in the flowing milk, and the capacity depends surely in the first instance on the size of the heating surface. Nevertheless it is a well made pasteur- izer of its kind, and needs only a few improvements to make it the best of that class made in the States. 38 After I had run my heater for a month I was amused to hear that K. Hansen & Schroder had made a heater whereby they obtain the same result by other means, and though not st rictly a centrifugal heater, I class it under these. As after all it is the centrifugal force of the dashers and the para- bolic shape of the drum which spreads the milk in a thin film over the heat- ing surface and elevates it. Fig. 27 represents this heater, consisting of a wooden covered steam jacket A, which is swung on pivots P. Steam enters at U above and the condensed water escapes through the water-lock W, both being connected by a union U. Fig. 27. Fig. 28. 39 The milk enters the tinned copper vessel B by the funnel- shaped cover C and is forced through a pipe (not shown). Shortly after this, or about the same time, P. J. Buaas (Denmark) constructed the heater "Triumph" in 1895, shown in Fig. 28. A tinned copper cylinder is closed tight by a cover in one end by using rubber packing and the patent fast- eners g. On this cover is a sort of funnel a through which the milk enters the cylinder and is thrown on the heating sur- face in a thin film and at the same time moved forward by the fast revolving screw wing, and elevated through the stand pipe b, nearly 8 feet if so desired. The milk left in the drum is drawn by c. The steam enters the jacket, which is well in- sulated at d, and the condensed water leaves at e. A safety valve is placed at f. A similar heater, under the same name "TRIUMPH," made by The Sharpies Company, Chicago and Westchester, Pa., is illustrated in Fig. 29, showing the open end of the hopper Fig. 29. and the cylinder head and propeller removed. A protecting plate prevents the steam from heating the place of entrance too much, both direct and exhaust steam may be used. I understand Mr. S. is contemplating constructing a revolving inner drum with a spiral propeller soldered on the outside in- stead of the present one. 40 From this time on the "self-raising" heaters became more general. Paasch, Larsen & Peterson (Denmark) make the heater shown in Fig. 30, which explains itself. The milk enters at A and is elevated to the conductor B, leading to the cooler. The steam enters at C and is forced to the sides by a plate protecting the can from being overheated. It will be noticed Fig. 30. that no elbows are used on the milk pipes, but T's which have caps so that each length of pipe may be cleaned like a gun barrel. Axel Malmquist (Denmark) built a heater where the main change consisted in dividing the heating jacket in 3 spaces. The middle one contains steam under pressure, the lower one contains the condensing water and the upper one warm water. He claims that by confining the hottest heating surface to the center scorching is made impossible. The new Bergedorfer (Germany) heater, Fig. 31, is de- scribed in (M. Z. 1899, page 354) as follows. Instead of the 41 usual stirrer in the inner vessel there is a cylinder B on the side and bottom of which are fixed wings or dashers F on the outside reaching close to the vessel and thus compels the milk which enters at the bottom from G to spread itself in a thin layer over the heat- ing surface until it reaches the top after reaching the desired temperature. It then goes over the rim of B and is forced downwards by the fixed cylinder C, which is attached to the Fig. si. close cover and reaches close to the bottom of the revolving cylinder B. The milk then rises in the inner cylinder C and leaves the apparatus at H, as indicated by the arrows. The smallest heats 2,800 Ibs. per hour from 86° to 215° Fah, and the price is about $188. The largest heats 10,800 Ibs., and costs $390 f. o. b. Bergedorf. Mr. Jos. Siedel reports favorably on this heater. REGULATORS FOR HEATERS. In working with continuous heaters the great problem is to be absolutely sure that all the milk that leaves the heater is of the desired temperature. Even if a man watches the thermometer pretty carefully he may miss it now and then. Hence the Royal Danish Experiment Station took up the work and Messrs. V. Henriques and Stribolt constructed the regulator shown in Fig. 32. It consists of a box attached to the side of the heater. In this is a spring constructed of two bars, the inner of steel and the outer of brass, riveted or soldered together. One branch is fixed firmly to the side of the box, while the other is left free to move. As the brass bar expands more than the steel, but is firmly attached to it, the result is .a lateral movement and this is utilized to shut off the valve on the milk supply 42 Fig. 32. Fig. 33. 43 pipe. Although this regulator worked fairly well, it did not remain long in use and the following system gained on it. T. C. Nielsen (Denmark) with his tipping regulator Fig. 33, proposed to solve this problem in another way by simply diverting the milk not hot enough back to the milk tank. This is done by letting the hot milk run into a cup AA with spouts on opposite sides. The cup rests on a frame d e, which is balanced on a three-cornered steel so that it may tip easily one way or the other to conductor f or 1. The balance is reg- ulated by two moveable metal balls g & h, so that a very small weight will tip the cup. To do this there is inserted a tube ab filled with mercury to the bottom of the, bulb, b. In a there is also a drop of alcohol which is expanded by increased heat and thus forces the mercury from a to b, and this is enough to tip the cup AA. As soon as the milk becomes cooler the mercury falls back in a and the cup turns the milk stream into the other conductor. By using alcohol of various boiling points the temperature at which it acts may be varied. The milk which is not warm enough may be made to pass a cylinder and act on a ball cock and thus either open the steam valve or partly close off the cold milk from the heater, but the main point is that the milk passing as pasteurized really has been heated to the desired degree. These regulators were introduced in 1895-1896, but in 1899 Mr. P. V. F. Petersen, in a lecture, declared that they had not been adopted in the practical dairy work, although he does not seem to condemn them altogether. There can be no doubt that there is a crying need for some such device not only for pasteurizing but also for regulating the heating of milk for separating. DANISH GOVERNMENT EXPERIMENTS WITH HEAT- ERS. When the Danish government proposed to make it com- pulsory for creameries to pasteurize all cream and milk bar- ring that used for cheese making, the Experiment Station from 1897 to 1899 again took up the problem of pasteurizing heaters writh special reference to their capacity and economy in using steam. The first improvement wras made by soldering on the out- side of the heating drum a series of rings (Fig. 34) at a down- 44 ward angle of 45°. These removed the water condensed on the drum quickly and thus prevented it from forming an insulating layer on the drum, and increased the capacity fully fifty per cent. In Fig. 35 is shown a re- modelled Fjord heater with 8 such rings. The second improve- ment was the fixing of an air cock (L. Fig. 35) on the waterlock V. This removes the air which is carried into the heating space with the steam and which accumulates there to the detriment of the heating capacity. The third improve- ment was fixing six horizontal plates (P) Fig. 35. to the dasher (E) which also increase the capacity by prevent- ing the mixing of the milk layers all having different temper- atures. Take it altogether, such an apparatus with a milk drum of 19 inc'hes diameter and a height from bottom to top of Fig. 34. the heatimg surface of 30 inches, will heat 8,000 to 10,000 Ibs. per hour (the last amount: when the surface is clean) from 104° to 185° — a wonderful result indeed. 45 B Later experiments showed how7 the plates on the dasher also tended to reduce the formation of foam and the appar- atus was changed as shown in Fig. 36. Just below the out- let (a) a plate (j) similar to those be- low, is fixed on the dasher, and the out- let is given the shape of a horizontal slit (5 inches long and J ^ inch wide), placed just above the top of the heating surface. Outside the outlet is soldered a jug- Fig. 36. shaped spout (b), so that the upper edge is just level with the cover of the apparatus. As the milk inside must always rise to the same height as in the spout, the outlet is always covered by a layer of milk (see dotted lines), which prevents the foam from escaping. Finally a plate (i) is fixed on the dasher immediately under the cover, and between these two plates the foam gathers and is submitted to the centrifugal force. The foam which is not destroyed, makes its escape through six holes in the center of the upper plate to the spout (d). The result is foam-free milk comes from b, while air and now and then a little foam' comes through d. The relative weight of foam-free and foaming milk is given as follows: Foam-free 100, milk from separator 71 to 72, from the milk pump 62 to 65, from the improved pasteurizing heater 94 to 97. The speed of the dashers is 280 to 300 revolutions. The above is taken from the report in Maelkentidende of an address by P. V. T. Petersen, Sept. 1, 1899. One of the last up-to-date Danish heaters constructed ac- cording to the principles just described is shown in Fig. 37 46 taken from the advertise- ment of the manufactur- ers, the stock company "Pasteur" of Banders (Denmark). It is hung on pivots U on a neat iron frame screwed on to the floor and ceiling. The steam is let into the well insulated jacket n from the pipe m, which is easily disconnected by a union. The condensed water leaves through the waterlock, having an air cock r. The tinned cop- per cylinder v is provided with rings or flanges o o, and the dasher c with plates. The milk enters at a and leaves through the lower opening e and what little foam which is not destroyed in the Fj^ 3" room d k leaves by 1. A. H. Reid, of Philadelphia, was the first American manu- facturer who introduced the Fjord pattern heater with the ele- vating device. Fig. 38. On Dec. 14, 1899, he applied for patent on an improved heat- er (granted July 3, 1900), where he introduces the steam tangentially through an unobstructed opening in the side of the casing, and where it travels free in the spaces between ribs or rings which are fixed on the heat- ing vessel as shown in Fig. 39, which explains itself. They differ from the Danish ring by the upbending of Fig. 38. of every other lip. Mr. Reid's complete pasteurizing plant, with the new heater, is shown in Fig. 102, page 99, and Mr. A. Jensen's cream pasteurizing plant is shown in the chapter on Pasteur- izing in Creameries. Fig. 39. This virtually covers the evolution of the Fjord heater up to 1901. SURFACE HEATERS WITH MILK EXPOSED AND COV- ERED. In Sweden De Laval constructed a well made if rather Fig. 41. 4S expensive combined heater and cooler, Fig, 40, which is in two sections, the upper one heated by hot water or by steam en- tering at b, with overflow at a, and the lower, one cooled with ice water entering at the union to the left and leaving at c. The milk is distributed from the cup on top and leaves at d. In Germrny Hr. von F. Hochmuth adapfed the Law- rence cooler to his purpose in a similar manner, as shown in Fig. 41. It is divided in three parts. The lower one acts as cooler, the wrater enters at the bottom and is then, when warmed at the top of the cooler led through a curved pipe into the upper part leaving at a. There the heat absorbed from the milk is utilized for the preliminary Fig. 43. heating. Meanwhile the center part is heated by steam en- tering at D and the condensed water escaping at C. We find the same objection to this apparatus as to the Laval, in the great drop, which requires the milk to be pump- ed. This led Mr. Hochmuth to modify it and construct one with the heater placed horizontally, Fig. 42, and also one with both heater and cooler in a hori- zontal position. Fig. 43. In ad- dition to this change, he also adopted a cover which protects the milk against the air as well as compels it to follow the curvature of the corrugated surface instead of flowing on top. Similar system was used by Lawrence, where the upper section was covered, but I confess to a liking for the open surface for heating and for the first cooling, always provided the air is pure Fig. 42. when the apparatus is used. 'Carl Thie/' (Germany) as early as 1886 adopted a system of heater Fig. 45, where the milk is not exposed to the 49 open air. It consists of & tin-lined wooden cylinder a between which and a cor- rugated cylinder is a per- forated steam coil o with ;-team entering at h, thus heating the water to the de- sired temperature read off on the thermometer b. The over- flow water escapes at p and is emptied at n. The milk flows from the tank x on to the curved cover which is perforated so as to distribute the milk evenly on the inside of the corrugated cylinder from whence it flows to the bot. torn and out by i find k, the thermometer m showing the temperature. Dr. Fieischnian heated 1,250 Ibs. of milk per hour from 66° to 140° Fah. with the heating water only 158°. Thiel used a similar constructed cooler, but of course any kind of cooler can be used. Kelch's (Germany) heater and cooler is showrn in Fig. 46? with a sectional view in Fig. 47. It consists of two cylinders A and B, the latter set in the former. The narrow space be- tween them K is used for either heating or cooling the milk Fig. 46. 50 "which is spread in a thin film over both the corrugated sur- faces by fine holes in the funnel shaped cover D. The bottom of the space K is covered with a ring Z, which lets the milk out by the faucet g. This heater approaches in effectiveness one suggested by me in 1894 for cooler, namely by having two corrugated •cylinders made with spiral corrugations so that the inner one could be screwed down in position, leaving only half or 'one-quarter inch space for the milk. I believe it would be the ideal heater (and cooler) where no motive power is to be used. The milk would hae to follow the corrugations somewhat as shown in Fig. 43. I once corresponded with manufacturers of copper expansion joints for large steam pipes, but the price seemed too high to make it practical. A very simple device is shown in Fig. 48. Mr. Bentley, of 14 Ohio, used it and I have also had one made, but with several sets of cans within each other. It is really an adaption of a cooler illustrated in Dr. Fleischmann's book, invented by Jell- inek Romanowsky years ago. A tube H is soldered in the center of a shot- gun can AAAA, having holes in the rim below. This is placed in a larger can BBBB. The latter is placed in a tank with water kept warm with a steam jet (or cold with ice if used as a cooler). The can AA is also filled with water, warm or cold, and the milk en- ters at H, flows through the holes in the rim of the can AA, and. passes up between that and BB and out at M. In Sweden De Laval solved the protection problem in a similar but more elaborate manner, as shown in Fig. 49. This apparatus consists of two closed double vessels fit- ting one into the other in such a way as to form concentric- narrow apertures of large surface, through which the milk is forced. The aperture is only about -J of an inch and the milk, which is kept in constant motion, is rapidly and evenly heated, without allowing any albumen to coagulate. Each vessel has a pipe (a) which passes down close to the A A Fig. 48. B 51 bottom; these two pipes are at the upper end joined at b where the steam enters. Both vessels are also connected by a pipe (c) by which the condensed steam escapes from the inner vessel into the outer, from which it again flows through the pipe (d). The inlet of the milk is regulated by an ordinary regulator cup (e) with float, same as used on the separators. After the milk has passed down through the inner conical aperture, it rises through the outer one and flows over the rim of the annular re- ceiver placed round the above named regulator cup, and flows off through the pipe (g). At the base of the outer vessel are fitted a faucet (h) (for drawing off the milk remaining in the apparatus after the work is finished) and a screw-plug (1) for emptying out the heating water from the outer vessel. The inner vessel is emptied of its water through the opening n, by means of a syphon. It is made in sizes to heat from 1,300 ft>s. to 3,600 ft>s. per hour. D. H. Burrell & Co., of Little Falls, N. Y., have also adopted this idea in their double surface heater, Fig. 50. It Fig. 49. Fig. 50. consists of a copper cylinder sur- rounded by a water jacket, and fitted with galvanized cast iron heads; the upper head having a removable cover, and the lower head having a screw collar on the inner side. Into the cylinder fits the inner core, which is held in place by being screwed on to the collar in the bottom of the outer cylinder. This screw joint be- tween the outer and inner vessels establishes a passage for the heat- ing water, which, being run into the filling funnel, fills both inner and outer vessels to the level of the overflow nipple. The steam is fed into the inner core by a cen- tral jet, and into the outer jacket by a second jet. The milk is in- produced at the bottom into the thin space between the inner and outer cylinders. As it flows up- wardly to the milk outlet it passes between the two hot surfaces. TUBULAR HEATERS. In France, Mr. F. Fouche constructed what he calls a multitubular pasteurizer. Fig. 51. The milk leaves the tank M and enters the bottom of the heater which is heated by steam entering at S. After passing through a lot of straight tubes the milk leaves the heater and enters the cool- er at the top. The tubes in the cooler are cooled by water from tank W. This apparatus fills the bill as FiS. :,\. far as excluding the air Fig. 52. during the (ait ire operation, but whether it has obtained any extensive use I do not know. It can be cleaned by loosening the top. Sturges, Cornish & Burn Co., of Chicago, has put on the market a tubular heater shown in Fig. 52. It consists of a horizontal drum with a larger reservoir in one end. In the drum is a battery of tubes about f inches in diameter and one end being accessible these can be cleaned like gun barrels, as they also open into the reservoir. In this there is a partition so that the cold milk enters at one side, passes through half the tubes to the other end and returns by the other half. The drum is filled with water through funnel on top and is also provided with an overflow; a steam jet at the Tee on the pipe b- low the bottom of the drum heats the water and keeps it in a lively circulation. This heater is certainly very effective and they also make vertical pasteurizers on the same princi- ple only the tubes are one inch in diameter which makes them easier to clean. The tubes are made of drawn metal tinned and are as smooth as can be. This heater can easily be converted from an aerating to a completely closed one by having a tight cover on the reservoir for those who believe in total exclusion of the air. A NEW DEPARTURE IN HEATERS. Lefeldt & Lentsch's (Germany) latest sterilizing and pas- 54 Fig. teurizing h eater "REGENER A- " is the result of the European eco- nomic spirit, and makes the cold milk cool the hot, while the latter heats the former, thus saving both ice and coal. The outside is made of iron and is insu- lated. Inside this are two curved tinned copper drums, which fit into each other, leaving a narrow space for the milk to pass. Fig. 53 shows a sectional cut of the heater closed while Fig. 54 gives a gen- eral view of it, and Fig. 55 shows it opened for cleaning. In order to keep the milk in motion while heating the drum con- nected with the moveable side is revolved by aid of the pulley shown. The milk enters at b, following the direction of the arrows, is heated by steam entering through C into the fixed drum, and when it reaches the end of the heating surface the thermometer shows the tem- perature and it commences the return trip and is cooled by meeting the cold milk, leav- ing the heater at e. The con- densed water is removed at a. The one with a capacity of 6,000 Ibs. per hour holds 372 Ibs. and there remains about 180 Ibs. when the work is done. This is drawn off by the cock at d. The apparatus was test- ed by the agricultural society and shown to heat the milk to 225° without changing its color or giving it any pro- Fig. 54. 55 nouiiced cooked flavor (?) It left the heater at from 101 to 119° below its highest temperature. The price is about 1500.00 in Germany. Kleemann & Co. of Berlin (Germany) have also utilized this coal and ice saving idea, but they make use of two separate Fig. 55. apparatuses. See Fig. 56. The one to the left is a high pressure heat- er with a cylinder re- volved by pulleys from below. The cold milk enters at h and meets the hot milk in the regenerative appara- tus to the right and passes, partly heated, ~* through the pipe B into the heater where it reaches the high temperature 1 e avi ng 2 through pipe A to pass back into the first Fig. 56 apparatus, mertir.g Tli:> cold milk and leaving partly cooled at G. C is direct si< ;uu ,-snd I) is exhaust steam inlets, E is 56 a faucet for emptying the last milk and F is outlet for ex- haust steam and I is outlet for condensed water. The price for both with a capacity of 6,000 to 8,000 fibs, per hour is about $812 f. o. b. Berlin. It is claimed to be easy to clean. As far as the incomplete description goes it seems that there are two cylinders inside the drum and that one is revolving while the milk goes between them, first up, then down and then up again. TANK HEATERS. To all the "continuous" heaters, the bacteriologists ob- ject— as before said — because even a large body of milk in transit there is no assurance that all the milk has been ex- posed to the high temperature for the time needed. On this principle Prof. Russell, of Madison, Wis., con- structed an apparatus illustrated in Figs, li-4, 25 and 26, which he calls a ''combined pasteurizer and cooler;'' this is a misno mer, it is a "pasteurizer;" if it were not designed to cool as well as heat it would simply be a heater. I point this out as there is a tendency to call the simple heating of the milk pasteuriz- ing; this is wrong, pasteurizing is both heating and cooling. Fig. 57. Fig. 57 — Diagrammatic side view of pasteurizer — i. v. — in- side vat for milk; s. c. — stop-cock in outlet tube; in. o. — milk outlet; 1. — lever to control stop-cock; o. v. — outside vat; w. c. — water chamber; w. p.. — water pipe (steam or water); ther. — thermometer in milk chamber; r. — brass rod to which i. s. (inside stirrers) in milk chamber are attached; r. — rod to 57 which o. s. (outside stirrers) are attached; c. — crank; p.— pulley. Fig. 58 — End view of pasteurizer showing double vat arrangement. — w. c. — water chamber; m. c. — rnilk chamber; RJ? Fig. 58. i. v. — inside reservoir for milk; o. v. — outside reser- voir for water; w. p. — Avater pipe; v. — vent of same; i. s. — inside stirrer in milk chambers; o. s. — outside stirrers, (three se- ries); r. p. — binding piece of wood to which i. v. is attached. The ends of this rest on outside wooden vat, o. v. Fig. 59 — Diagrammatic view of pasteurizer from above. — in. c. — milk chamber bounded by continuous black line; w. c. —water reservoir surrounding same; r. and r'. — rods from which stirrers are hung in milk and water chamber. Fig. 59. Left hand of figure shows wooden frame that supports the gearing for stirring; p. — the pulley on axle for automatic power; c. — hand crank. Lower figure S. — Face view of one of stirrers in milk chamber. These can be removed from rod (r). Lower half of two stirrers is solid so as to mix the milk more thoroughly. The apparatus consists of a wooden vat o v Fig. 24, with one or two narrow tin vats I V. A rod R. Fig. 57, worked backwards and forwards by a crank, carries the milk paddles I S, and is connected with the two rods R', which carry the water paddles O S. One pipe 58 W P, introduces both water and steam. S on Fig. 59 repre- sents the milk paddles. The whole is covered with a cover. The milk is filled in and the paddles are kept moving during heating, and when at the desired temperature is left for twenty minutes. Then the hot water is drawn off and cold water is turned on during constant stirring until it is about 70°. When cold enough the milk is drawn by M O, by opening a special con- structed faucet S C, with a straight cylinder. The tempera- ture is observed at T H K. This apparatus is used successfully in the Madison Ex- periment Creamery (Dairy School), for pasteurizing small amounts of cream sold in the city, and in many other pasteur- izing plants. It is made by Cornish, Curtis & Green Mfg. Co, Fort Atkinson, Wis. Among the tank heaters used for pasteurizing must be mentioned the improved Boyd cream vat, Fig. 60, miscalled "Cream Ripener," made and sold by Sturges, Cornish & Burn, of Chicago. Potts' Pasteurizer, sold by Creamery Package Mfg. Co., Chi- cago, has been improved upon so as to heat with hot water circulated by the aid of a steam jet instead of using steam directly in the jacket, Fig. 01. The drum is made of wood Fig. 60. D— X- Fig. 61. 59 and the inner cylinder of heavy tinned steel plate or tinned copper. There is a space of one inch between the two. The water connection is at E, above which connection may be made with both the regular wrater supply and an ice water tank. 8team connection is made at A with a jet at C, which heats the wrater in the circulating pipes, GGGG, and in the space between the drums, the flow being upward through a check valve at'D. An overflow escape is provided at B. At T L there is a cotton cup connected with the inner cylinder by an air pipe which allows steam and gas from the milk to escape. Y is an air vent open while filling the water space. The temperature of the milk is taken by a thermometer M in the cover V, and that of the water in the jacket at S. Inside the inner drum is a curved breaker, which stirs the milk or cream and, thoroughly mixes it. When cooling, the cold water is turned on and passes directly into the space between the drums as the check valve at D prevents it from getting in- to the pipes G. The pulley F revolving at 60 to 90 revolutions will make the drum revolve 10 to 15 times per minute. The outlet pipe N is put on at P when ready to draw the milk off as is the lever Z on the cock, which is so constructed that it may be easily taken apart for cleaning. It is claimed that with water at 150° and the milk at 130°, the temperature in the latter will rise showly to 140° after shutting off the steam, and that it may be cooled in 30 to 35 minutes on the large machines and 20 minutes in the small ones, but it is not stated what temperature the water must be to do this nor the flow. It is made with a capacity of from 400 fibs, to 2,000 Ibs., at prices from f 125 up to $250. If cooling by circulating brine is desired the inner cylinder must be made of copper and an extra charge is made. Of all tank pasteurizers this seems to have gained the most favor, and at Madison Dairy School they seemed very much pleased writh it, but I cannot say that I like the auto- matic vent T L, because it seems to me to be difficult to keep clean, and it would be a small matter to have a simpler vent and let the operator open it now and then. Bitter (Germany), who also condemns all continuous ap- paratuses, constructed a small one where a dasher revolved between two steam coils in n round tank. It is evident that the keeping of these coils cle;ni must ivlegato this apparatus to the museums as impracticable. 60 In the U. S. Agricultural year book for 1894, Dr. E. A. DeSchweinitz has a treatise on "The Pasteurization and Sterilizing of Milk," from which I gather that the Appleberg Hygienic Milk Co., at Rawlings, N. Y., has patented an "ap- paratus" for pasteurization. It consists of a wooden box four feet square with a hinged lid. On the bottom is a steam coil. Inside the coils the (rectangular) milk cans, holding forty quarts, are placed and covered with perforated tin lids to permit the insertion of a thermometer. The cans fit closely together inside the coil. During the process, the milk is kept thoroughly stirred (how?). The temperature varies from 16° to 180°, and steam is turned on from twenty to thirty minutes. The milk is filled hot into the glass jars, which are placed in ice water to cool. At Danby, N. Y., is also a plant for "sterilizing" the milk in bulk, hot water being used instead of dry steam. HEATING BY DIRECT STEAM. Under the heading of tank heaters I must mention the system of heating by leading steam (exhaust or direct) into the milk. This has been used in some German creameries for skim milk on the "Kort- ing" system, illus- trated in Fig. 62, which shows how the current is direct- ed diagonally against the sides. The heater consists of a trumpet-shaped end to the steam pipe with openings just behind the point of the steam jet on the same principle Fig. as our steam jet pumps and heaters. See Fig. 62. 61 A similar idea has been adopted by Mr. Bentley, called by him a "Germicide." This is indicated in Fig. 63, by two wide tubes in which two steam jets blow in different di- rections, causing a current in the milk, as indicated by the arrows. The steam pipes are joined together above (not shown in illus- tration) with a drip ar- rangement in the center so Fis- 63- as not to introduce any of the steam condensed in the pipes. In Fig. 64 I have shown the simple Barber noiseless heat- er intended for water with which I have made start the cur- rent in any desired direction. By modifying this, a "heater" for direct steam can be made by any- body at a nominal cost. Steam en- ters at S through the reduced open- ing of the nipple s. The milk is sucked in at m and ejected at e. Mr. Newton, ex-President of Iowa Dairymen's Association, was the first to suggest the plan of elevating the skim milk into a bucket placed in the tank, and then have an exhaust steam pipe enter into the bucket, thus heating the milk, and Mr. Jensen, of Kansas, constructed a skim milk heater by having the milk pumped into a trough placed in the skim milk tank, and in the bottom of this trough is a perforated steam pipe whereby the milk is heated. In heating milk directly with steam there is, of course, a dilu- tion. In one test I made it was 7 per cent, but it is often more, and add to this the danger of contamination from im- pure steam and it will be seen that it should not be encour- aged where the milk is intended for human food. STOKAGE TANKS. In view of the assumed necessity of keeping the milk or cream at the high temperature for 20 or 30 minutes, if it is Fig. 64. 62 to be sold and not manufactured, and in view also of the diffi- culties of heating all the milk in a body when we have to handle large quantities such as must be handled at milk shipping stations if pasteurizing is ever to be introduced gen- erally, I have suggested the following plan : Use any continuous heater which you find best, but in- stead of running the milk directly to the cooler, run it into a storage tank, which should hold one-third of the hourly ca- pacity of your heater and cooler if you desire to keep the milk for 20 minutes at the high temperature or one-half if you want to keep it 30 minutes. This tank may either be built with water space filled with water at 155° or better still be properly insulated so as to hold the temperature within 5°. By having one partition in the tank and two attached to the cover the milk is compelled to go to the bottom first then up, then down and at last up and out to the cooler, and I challenge bacteriologists to show any reason why this ar- rangement does not solve the problem of combining a contin- uous apparatus with the strictest bacteriological demands! What is more, I believe that this system of instantaneous (so to say) heating is better than the slower heating of a large body of milk in a tank unless indeed all the milk arrives at once and is left for hours at the dangerous temperature. D. H. Burrell & Co. have adopted a better plan, and have all the partitions soldered on the tank, every other being soldered to the sides and bottom, and every other being open at th« bottom; and A. H. Reid has adopted a vat similar to the Danish Weston separator heater. (See Fig. 102.) Even if it should be found necessary to have several tanks each of a capacity to hold the milk absolutely for the required time, as proposed by Mr. J. D. Frederiksen, this would be better than the slow heating and cooling of 3,000 or 4,000 Ibs. of milk. If the milk is 60° or above, it is surely better, the quicker it is heated up. While I express this as my belief at present, I hope to see the experiment stations take the matter up in a practical manner free from scientific punctiliousness. 63 CHAPTER III. THE PASTEURIZING COOLER. I have shown how in some pasteurizing apparatus the heating and cooling may be done in one vessel. I have also shown some of those where the same construction is used for both purposes separately. It remains now to mention a few of the coolers which have been used. COOLERS WITH EXPOSED SURFACE. Among those made on this plan the most effective are un- doubhtedly those made on the Lawrence and Laval plan. The former has indeed been so thoroughly copied both in Europe WARM MILK A B. G and America by most of the manufacturers, who thus have paid the inventor a high compliment. The latter is illustrated in the lower part of Fig. 40, and the former is represented in Fig. 65, which shows cross sections of the three different styles of constructing this cooler, A, B, C. To these should be add- ed the cheap tin cooler made in America under the name of Dan- ish Weston cooler, and the cooler made by A. H. Barber, of gal- vanized iron pipes, with close el- bows and a partition of tin sol- dered between them. 'The Lawrence style of coolers are made in America by the Star Cooler Manufacturing Co., Vermont Farm Machine Co., and A. H. Reid, of Philadelphia, the last of which I illustrate in Fig. 66, and are, when well made, R SPACE DMILK Fig:. 66. 64 undoubtedly among the most economical as far as utilizing the water. It requires always a considerable fall, and this has pre- vented their use in many creameries.' Of the three constructions I believe C is the one wrhich utilizes the water most thoroughly when made, with a very narrow water space, but this is less important where the supply of water is large enough. Modifications of this cool- er, made to do away with the objection of its drop height, have been made. I illustrate a German one in Fig. G7, which is also used as heater. This style has been in all angles down to nearly hori- zontal, as in Hochmuth's, but the great objection has been the tendency of the cold milk to flow straight down on top of that which is in the curves, thus diminishing the effect considerably. Hochmuth tried to overcome this in Fig. 43, where the cover is corrugated similar to those of the cool- er. In Fig. 68 we have the W. Smith cooler, which style is very popular in Europe. B is a circular corrugated surface with a smooth cylinder inside, between which the water circulates. The milk flowrs from the distributor A over B into the gut- ter and out at D. While it in one way is more compact than the Lawrence style, it uses only one side of the cooling water and has the same objection of high drop, though not in the same degree. Several years ago Mr. U. S. Baer, the expert separator man working for Laval, tried to overcome the objection of the creamery men to coolers with considerable fall and con- structed a long shallow 1 foot wide gutter with a double bot- tom, in which the water was made to go zig zag by half parti- tions. Fig. The only difficulty was the same as with all surface heat- ers that when not perfectly level the milk would run on one side only. Mr. A H. Barber, of Chicago, who made this cooler, improved on this by making it as illustrated in Fig. 69, giving a view from above with part exposed and a cross section X M, which shows the corrugation which compels the milk to run in the little gutters and increases the cool- ing surface. Also in P the partitions which turn the current of the water which flows as the arrows show on the exposed part of the sketch. The milk flows, of course, in the opposite direction and on a length of 8 feet, 2 inches drop is fully enough; indeed, they may be placed nearly level. Where they are not desired to be used as conductors as well as coolers they may be arranged zig zag, as shown in Fig. 24. In a trial I made, 22 feet of this cooler reduced 900 fbs. per hour from 156° to 102° with the cooling water 74°, and the next 20 feet reduced it to 55° with water circu- lating over an ammonia coil (about 90 feet, 1 inch) which kept the water at 50°. Mr. Barber makes these double width to order for pasteurizing purposes, and, if de- sired for brine circulation they are made of tinned copper. Numerous other surface coolers for running water have been devised, but these are the principal ones. We now come to the coolers with protected surface. While I feel inclined from a practical standpoint to over- look the demand of bacteriologists for a heater with covered surface, I am more inclined to acknowledge the value of protection against the air during cooling, especially the last cooling. Prof. Russell suggests the one showrn in Fig. 70. It con- sists of twro tin cylinders with only J-inch space between each other, and here the milk flows through (MC). The cylinders can be taken apart at one end and inlet and outlet pipes can —5 6G 93 o p I s: « P o ^ ^ g g^ 32 p O SC PJ w <* 3 °gK^^|^0 O §, O p -- 3 O -t | 3 £ *? S & I ^-. c-+- P ,> O rt ? 3 " S 5" ^ ^ S CD ff x- 0 B B ^ c 3 I ' trt c t± • S ' E B -"*• ' o | M f1 g r < ' J" f J I ^ I" r- ^ g" illiis 1 II £ § ~- 5- a 1 o ^§33 50 O tr1 p ^, • e i • 1 1 B 2 g Ct p a- p; & &. o ^ 3 S ^ g O ^ £0 O i / 20 B » * S B ^ - — n| p a cr o r- ^ B 67 easily be removed by "a ground joint like an ordinary sink plug." They are submerged in a tank which is filled with water, which also passes through the inner cylinder as indi- cated in the illustration. With this cooler and cold water the milk can be reduced from 25° to 40°, says the professor. I have shown how Hochmuth and Lawrence protected the milk against the air by a mantel, and the exacting Prof. Bitter protected the Smith cooler, Fig. 68, by a cover. Indeed nearly all these surface coolers are easily cov- ered at a slight expense for those who so desire, and unless the air is pure it is certainly safer. A. H Barber & Co. makes coolers similar to the Hill heater, and on the same principle are the Miller coolers de- scribed with his heater on page 36. CENTRIFUGAL COOLERS. THE BERGEDORFER Machine works (Germany) make a cream cooler illustrated in Fig. 71. It consists of an in- verted cone of cast iron in which revolves a simi- lar shaped drum driven by P. The cream enters from C, the lower bear- ing of the drum, and escapes through the per- forated upper part of the drum into the gutter and leaves at CR. The water enters at \V and overflows through the siphon O. The cream is here, as in the centrifugal heat- ers, spread in a thin film over the drum. The speed given is 800 revolutions per minute. If the friction of the water be not a too great objection to this system in larger apparatus, it seems to me there are great possibilities in de- Fig> 71. 68 veloping this idea. I have thus suggested that the drum be rotated by aid of the cooling water. It may also be used for elevator, as indeed it is in Fig. 71. The drum being wider at the top spreads the cream in a thinner layer where the cold water is sprinkled on the top of the drum, the lower three-fourths only of which is im- merged in water. They are made to cool from 800 to 1,200 Ifts. per hour — the latter being able to handle the cream from 8,000 Ibs. of milk. ICE COOLERS. Where water is scarce and ice plenty the cream cooler originally designed by Prof. Fjord, Fig. 72, has been used. A tin can is placed inside another, leaving a space to be filled with crushed ice. On a bracket there is a funnel with four curved outlets. This is revolved by the action of the milk, which thus sprinkles itself against the ice cold walls of the can, flowing to the bottom and out. Fig. 72. Prof. Russell suggests the ice cooler shown in Fig. 73. Finding that it was difficult, if not impossible, to cool the milk sufficiently with water, he proposes to have three rec- tangular reservoirs made as shown in the cross section. When the milk leaves the water cooler it flows down the' side of the inner ice box, which is corrugated, and close to one side of the milk box M, which should be large enough to hold all of the milk from one heater. 69 The bottling arrangement by siphon explains itself. Fig. 73. Fig. 73. — Sectional view of Ice Cooler. — w. — cold water chamber outside; m. — milk reservoir; r. — receiver from the pasteurizer, milk flows down corrugated side of the chamber and is collected in (m.); s. — siphon arrangement for drawing off milk. Arrows in water and milk chamber show direction of current. It stands to reason that any and all of these ice coolers are not doing their best work unless there is some provision for stirring or moving the iced water, and while they may be used with water alone, they will be less effective, and it may be laid down as a rule that ice or a refrigerator machine is a necessity if pasteurizing is to be successful, unless indeed a flowing well of 48° or less is available. 70 CHAPTER IV. PASTEURIZING IN THE CREAMERIES. First as to skim milk. I have mentioned how it is much more practical not to pasteurize the skim milk, but to simply heat to 185° or 195° because this hot milk when poured into the cans will virtually kill any bacteria which may be in the little milk left in the cans, and pasteurizing : heating and cool- ing, should only be done where the cans are first cleaned and steamed, and even then I doubt the economy unless indeed a large flow of cold water might reduce the cost of cooling to next to nothing. It has been slow work enough to induce our creamery men to heat the skim milk by a steam jet (direct or exhaust) into the milk, so that it is in fear and trembling that I request those who do this to figure a little on the dilu- tion and the increased cost of hauling this water back to the farm. It is at least worth considering whether this counter- balances the expense of one of the modern heaters which may be used chiefly with exhaust steam. One thing is sure, every creamery ought to heat the skim milk for the protection of its patrons, and when once they (the patrons) have learned to appreciate the hot sweet milk then the butter maker will have his reward by getting better milk delivered, because if the patrons deliver milk too sour to heat they will get it back loppered. That this is the result has been testified to by too many creamery men to doubt it. And it also removes the danger of spreading tuberculosis, but full security against tuberculosis in the continuous heater is claimed by Danish authorities to be obtained only at 185°; indeed creameries are compelled by law in that country to heat it to that temperature. One trouble in heating the milk is foaming. A device to prevent this made by C. Mikkelsen (Denmark) is shown in 71 Fig. T.'U. The skim milk vat is made of heavy tinned steel plates with angle iron, round the top edge. This al- lows the clamping of the cover firmly and tightly. In Fig. 73%. the cover is an opening into which fits the half cylinder which is provided with two dashers revolving on a shaft driven with a cord pulley. The skim milk enters the vat through a closed pipe and the foam rises against the cover, where it is caught by the dashers and thrown against the cylinder, thus releasing the air which escapes through the ventilating pipe. The latest Danish heater (See Fig. 37) kills this foam by having plates on the dasher. SHALL WE MAKE PASTEURIZED BUTTER? This is a difficult question to answer, as regards our home market, and yet I believe that it would pay in the long run. First of all it wrould secure us a better price for our surplus to be exported, and it cannot be denied that such sur- plus affects our home prices, more or less. If an unpasteur- ized surplus of 10 or 20 million pounds of butter of the usual varying quality has to be disposed of and only 16 cents can be realized, it is evident that the holders will rather take 16 J cents at home, but if pasteurization would help us — as I know it will — to a greater uniformity and a better average quality of this surplus and thus raise the export value to 18 or 19 cents, it is evident that no butter would be oflVrrd for less than that price. But I believe further that even for our home markets it would pay, because by careful ripening of the cream, we can get a uniform clean flavor and yet high enough to please, and much greater uniformity. It is the uniformity which 72 lias helped to introduce oleomargarine to many of our hotels and restaurants and not always the greed of the proprietors. They find that there is less kicking made by their patrons on a uniform "neutral" oleomargarine than on fine flavored butter today, rancid or off-flavored tomorrow, and indifferent the next day. In creameries where perfect milk is delivered all the year round it would be foolish to pasteurize. I know well enough that I am perhaps before my time in taking this position, as not six out of ten, aye not four out of ten of our creameries are in a condition to pasteurize with any assurance of success. Only when we have buildings that may be kept clean will it be practical to adopt this sys- tem. There is no need of fancy buildings like the German creamery illustrated in this pamphlet on page 77, but brick buildings with cement floors and walls finished in cement, with plenty of light and ventilation, as well as good drainage and clean surroundings, is a necessity. If individual cream- ery men who, alas too often, rent a rotten building will not reform, it is high time for the farmers to co-operate and put up such a building rather than continue to patronize the present average creamery. It would certainly pay them well. Our butterniakers have lately learned the value of a "starter," but do they stop to consider the uncertainties to which they remain a prey? Sowing wheat in a weedy field is an old simile, but nevertheless true, and pasteuriza- tion will certainly help him in getting uniform results from his work. I am not prepared to urge those who want to make pas- teurized butter to adopt the heating of the new milk and skimming hot, but on the other hand I dare not condemn it. Personally, I should prefer to pasteurize the cream and heat the skirn milk, as it comes from the separators. This is not a treatise on buttermaking, and hence suffice it to say: Con- tinuous heaters are satisfactory for this purpose. Cool the heated cream quickly down to ripening temperature, say 70° to 80°, and add your starter, but be sure it is a good one, because you will have no lactic acid bacteria that might help to remedy your mistake, as it happens when using an inferior starter in a good unpasteurized cream. On the making of the starter will you stand or fall. When nearly ripe, say 34 to 35 cc on the Mann's test, with cream 25 or 30 per cent fat, 73 cool down to 46° or 48°, and bold it there for not less than three hours and you will have no trouble with the "body" of your butter. Do not attempt to pasteurize unless you have complete control of your temperatures. In Fig. 74 is illustrated a Danish outfit with automatic Fig. 74. cream elevator, an old Fjord heater and Smith cooler and three cream barrels. In Fig. 75 is shown an English continuous pasteurizing outfit made by the "Dairy Supply Co.," London. To the Fig. 75. left is shown the typical English milk can (called milk churn in England) on a self-dumping elevator, which delivers the 74 milk in the vat. The heater is of the Laval type shown in Fig. 17, and the cooler is of the ''Smith" pattern, Fig. 76 shows a Danish creamery outfit with three Triumph heaters, the construction of which is shown in Fig. 28. The milk is received in H, from where it is run into the drum A, which has a steam mantel and a revolving horizontal screw, which heats the milk to separating temperature and elevates it into the separator. From the separator the cream runs into a similar heater C where it is heated to 150 and then elevated to the cooler D, from which it runs into the cream tank E. The skim milk runs into the larger drum B, and is heated to the boiling point. Fig. 76. On page 99, Fig. 102, is shown the A. H. Reid outfit for pasteurizing city milk. By removing the hot milk storage tank it will represent one suitable for a creamery. In reply to an inquiry about shipping hot cream from skim stations, I received the following reply from "the largest Creamery System in the world:"1 " * * * We have about 100 Pasteurizers and cool- ers out (the "Jensen") and the rest of our stations are pas- teurizing and cooling in cans, but just as soon as we can get the machines shipped we will pasteurize in them at all of out- points. "Now as to our success in shipping hot cream, will say 75 it cannot be recommended to any great extent, as the cream invariably will show a scorched flavor that never leaves the butter after it is made. We are shipping cream hot from two or three points on account of not having sufficient water supply. Shipping hot should not be recommended when as cheap an arrangement as the Jensen cooler can be had, that will bring the cream down within two or three degrees of the temperature of the water used, and only using about three to four times as much water as cream run through. "We think pasteurization is the only solution, as our experiment last year with held pasteurized butter turned out fine. The goods sold for fresh made butter on all the prin- cipal markets four to five months after being made. We pasteurize at our individual Skimming Stations and par- ticular care is taken that nothing but first class milk is re- ceived. "We think the demand we are having for our butter this year is something great, and the extra price we are getting for our product would pay for putting in pasteurizers on our whole system in two months. "Yours truly, "THE CONTINENTAL CREAMERY CO." Topeka, Kan., June 3, 1901. But the difficulty is to get cold water and enough of it in many localities, possibly if the modern low temperature of 140° could be maintained that would do away with the cooked flavor. SOUR CREAM has been pasteurized by Mr. Bentley, of Circleville, Ohio. Not having tried it, I cannot express any opinion, and regret very much that the experiment stations have not at once taken the matter up. I lack information about the degree of acidity, but if it is sour enough to have wheyed off, leaving a very rich cream, I can understand it. In that case, I presume, the curd, hard- ened by the heat, will settle to the bottom and not be incor- porated in the butter and cause white specks. Mr. G. B. Lawson, of Grinuell, Iowa, writes me that he has been converted from his doubts by practical tests, and hence I presume that even if it will not do under any and all circumstances, there is enough in it for every gathered cream- eryman to investigate. 76 The fact remains that if there is any curd at all in the cream it will be hardened by the heating and, if not elim- inated, cause more or less white specks and a very crumbly "body." fThat gathered cream which often has a bad taint will be improved in flavor by pasteurizing is sure enough, but, if possible, I would rather see a system where the farmers learned to pasteurize it themselves or to deliver sweet cream. I illustrate a cream pasteurizing outfit in Fig. T6J, used by the Continental Creamery Co. at their skim stations, and made by A. Jensen, Topeka, Kan. The heater is virtually on the Fjord plan, but the dashers are made (like those in ice Fig. 76l/2 cream freezers) to hug closely to the wall which, Mr. Jensen claims, prevents all burning on. The cooler is of the Mc- Pherson type, but the water is let in from four sides and by the aid of nozzles set in a lively circulation. With five times the quantity of water it will cool to within four or five de- grees of that of the water. OF THE UNIVERSITY f F 77 78 CHAPTER V. THE CITY MILK SUPPLY. The daily inilk consumption in the United States of Amer- ica does not aggregate less than 5,000,000 gallons. It takes about 2,000,000 cows to produce this, and an army of 200,000 men to care for them and milk them. So this is no insignificant industry and it deseryes more attention than it has had up to date. We have in the States twelve dairy papers, and only two of them are exclusively devoted to city milk supply — The "Milk News/' of Chicago, and the "'Milk Reporter,7' Decker- town, N. Y. Owing to the rapid development of railroad facilities ra- diating from all our great cities, the aspect of the city milk supply has changed greatly from the time when the source of supply of a necessity was very limited. It makes but little difference now whether the milk is produced within a few miles or within seventy, eighty, or even two hundred miles. With refrigerator cars the milk hauled 100 miles by rail is often better off than that hauled 10 to 12 miles by team. KEEPING ACCOUNTS. Hence producers of milk are now virtually compelled to base their prices on the price of butter or cheese and no com- bination of producers will ~be strong enough to ensure a hie/her price than that with a reasonable addition for the necessary ex- tra expenses. If this is correct — and I challenge anybody to prove it otherwise — then the producers of milk for city con- sumption must (like those producing it for butter and cheese) carefully study the problem of cheaper milk production, economy in marketing and reduction of unavoidable losses. Cheaper milk production depends first of all on the kind of cows kept, and while many farmers may make a pretty 79 good "guess" at the relative value, it is astonishing how they will be surprised at the result of a systematic testing and account keeping. Many a cow that has made a good im- pression by a great flow of milk for a few months, will be found at the foot of the list at the end of the year! It is a surprisingly lack of business system not to know exactly what each cow is paying for her board, and it is much less work than people believe to rule a book like this. Weekly recard of Cow No Born The calf dropped Served Due Date of test. MILK IN POUNDS. Babcock test. Pounds Butter Fat. REMARKS. Morn- ing. Eve- ning. Total. For week. 1 and weigh each cow's milk once a week, testing it, if not once, then every other week. I say testing because it mat- ters not whether the milk for city supply is now paid by the gallon, it is only a question of time when it will be paid ac- cording to butterfat. Any spring scale hung up in the stable will do, though I prefer other scales, say some- thing like the Mahler (Ger- many) scale illustrated in Fig. 77. It is made (as shown) to be bolted to the wall or for stand- ing on the floor and has a desk for the record book. It seems to me that this should be more reliable than the spring scales, which will sooner or later be affected by rust. The keeping of such records will help to create an interest in the work of the milkers, an am- bition to keep up the flow. If co-operation is possible, the formation of TEST AS- SOCIATIONS on the Danish plan is to be recommended. 80 Having the right kind of cows, the next question is the feed, but that is also too broad a question to take up here and Prof. Henry's book, Feeds and Feeding, should be read by every farmer. I shall confine myself to repeat a much needed reminder as to the economy of providing soiling crops in or- der to keep up the flow of milk if pastures give out, and to endorse the use of silage in moderation as the great "milk cheapener." THE STABLE. Cows will produce more and healthier milk if kept in well ventilated and lighted stables, and there is no need of ex- pensive, fancy buildings. I quote from my A, B, C in Butter- making: "We may even make, fairly good ones with a clay floor and the walls and roof of straw, if we only provide ventilation and light. The latter calls for the heaviest cash outlay, but sashes are now so cheap and the value of light of so great importance to the health of the cows that there is no excuse for not having plenty of it. As to ventilation, I give in Fig. 78 a cross section of a stable 14 feet by 36 and 8 feet high. A wooden flue or two A A is placed along one wall and made high enough to give some draft at least four feet above the ridge of the roof. On the opposite wall are inserted two or three flues like B B, or, if the wall is a double boarded one, the air may be taken in by leaving a board out between two studs on the outside at K (on the piece of wall shown) and another one on the inside at N, but in that case a board M should be nailed in a slanting position with end pieces on either side so as to give the air a slant in direction of the ceiling. As to the size of the flues, Prof. Kins, of Madison, Wis.7 considers that for 20 cows, they should have a cross-section 2 feet by 2 feet. The intake of fresh air need not be nearly 81 so large, as there are always leaks at windows and doors and it is better to have several small intakes to prevent draught. This principle — air circulation without draught on the cows — can be applied to a straw stable as well as to the most ex- pensive one. Comfort is an important element in cheap milk produc- tion, and while fixed stanchion may make it easier to keep the cows clean, we need only observe them when lying in the pasture to know how cruel and unnatural their position must be in those "animal stocks." Tying them, or — if it can be afforded — one of the mod- ern stalls like the "Bidwell" or the "Drown" are the only right systems and a liberal supply of bedding will not only help to keep them clean and make them comfortable, but in- crease the manure heap, which the Danish farmers call their "gold mine." To keep a cow tied up all winter is in no way a natural treatment, and though it is done by many good dairymen (thus universally in Holland and Denmark), the trend is now to do as Mr. H. B. Gurler recommends in his "American Dairying" give them lukewarm water outside, and if the weather is fairly mild let them remain there an hour or two at their option, but this advice should not be misunderstood as a defense for those farmers who turn their cows out to drink through a hole in the ice on the watering trough. The more the cow is deprived of exercise, the greater the need of keeping the pores of the skin open by daily carding and brushing. Indeed, this is not only a question of health (cheap milk production), but also of cleanliness (pure milk). It is a wonder to me that the farmer who will give his time willingly to keep his horse clean, begrudges it to his cows. It is a question of health in both cases, but in the latter it is also a question of health to his own family and those who may drink the milk. To illustrate this, Prof. Backhaus (Germany) tried with two cows, grooming them seven days, then leaving them four- teen days without grooming, and then grooming again for seven days. The result was in the fourteen days of each period: Grooming. No Grooming. Yield 575.4 Ibs. 536.4 Ibs. Total fat 23.06 Ibs. 21.33 Ibs. —6 82 This makes an increase of i It), butter per week in favor of grooming, which helps to pay for the extra work. Whitewashing, at least twice a year, acts not only as a disinfectant but increases the light in the stable. It is a comparatively easy job if a spray pump is used. MILKING AND MILKING MACHINES. There is no doubt but that the greatest trouble of milk producers is to get good milkers — men or women. I say women, even at the risk of being called un-American, because I deem it no unwomanly work, provided the stables and their surroundings are kept as clean as they ought to be, and because women, as a rule, really make better milkers than men. They have more sympathy with the cows, as a rule; they under- stand, as Ex-Governor Hoard says, the "motherhood" of the cow better than men. Milking is not a popular job because it is so confining; it has got to be done at regular hours, and no political or social engagement may interfere with it. This cannot be helped, but what can be helped by the milk producer is to pay their men (or women) decent wages and to refrain from running in milking as an extra chore instead of making it part and parcel of the day's work. A rough, noisy milker should not be allowed to stay a single day and cleanliness should be encouraged by providing a clean stable and clean surroundings, as well as water and towels for washing the hands. The fact is that but few milk producers realize the im- portance of having the right kind of milkers, not only to secure pure, healthy milk, but to secure a large yield. Few men realize the necessity of the milker making friends with a cow — in fact to get her to "adopt" him — in order to make her give all the milk possible. And this is the reason why I have been and am a little skeptical as to the possibilities of milking machines, so much so that I do not propose to illustrate and explain the various efforts in that line, but refer investigators to Dr. Stohmann's book where a full list will be found. Milking is not a pure mechanical work, and the cow compared with a ma- chine is but a lame simile after all. In my estimation, the best milking machine is a good, 83 stout boy or girl, man or woman, who ge-ts well paid and a little extra promised if the annual yield of the cows milked exceeds a certain amount. The question of milking is fur- ther treated in the chapter on sanitary milk, where nearly all the suggestions given may be adopted (somewhat modi- fied) more or less by any and all milk producers to their own advantage and for the benefit of humanity. CARE OF THE MILK. The question of the care of milk for city supply is an all important one, but I regret that there is a general inclination to make a distinction between that and the care given to milk delivered at creameries and cheese factories. There ought to be none, at least as far as to the shipping station. Having provided a clean stable as shortly outlined and having provided sound and fairly balanced food and pure water, the next question is the care of the milk. Even with all possible precaution against contamination, there is always need of some kind of purification. The means of doing this may be classed as straining, filtering and clarifying by centri- fugal force. STRAINING. On few subjects has there been so much misunderstand- ing as on this way of purifying milk, and it is a noteworthy fact that Swiss cheesemakers prefer their patrons not to strain the milk because they may then see how careful the milkers have been in excluding straw, muck and dirt. There is a good deal of sound sense in this idea, because generally the straining of the milk is a delusion and a snare, and pre- vention is better than cure. Take a slovenly, careless milker, milking say ten cows. He gets up cross and imparts the same feeling to the cow, who promptly kicks and splashes some dirt in the first pail. This is kept back in the strainer and the milk of the next cow7 and the next is poured over it, nicely rinsing all the fine dirt and bacteria off the coarser and visible dirt and straws into the milk can. Many are the devices, more or less effective, (generally less) invented to prevent this, but, as far as I have seen, they are all more or less difficult to keep clean. I prefer therefore a simple fine wire strainer to catch straws, etc., and beneath 84 this a simple piece of light flannel fixed over the can with a deep sag in the middle by using four clothes pins on the edge of the can. If this is done, and if the milker will take the trouble to change or rinse it out at once when there shows any unusual amount of sediment, then all has been done that can be done under ordinary circumstances. Of the hun- dreds of various strainers, I illustrate only one, introduced by Mr. John Boyd (Chicago) in Fig. 9 which explains itself. This re- duces the danger of washing the coarse dirt to a minimum as the milk will not be forced through it from above, and if the funnel tube were made with a tee and cap so as to be easier to clean, it would be a great improvement. The milk enters through the outside funnel and rises up through the inner one (over which is fixed a piece of flan- nel with a ring), and overflows into the can provided with a gate valve. I also— chiefly as a curiosity— illustrate one of the latest German strainers, the "Josef Fliegel," in Fig. 80. This Fig. 79. Fig. shows how far they go in their attempts in straining. It ex- plains itself, being filled with gravel, which, of course, must- be washed and sterilized every day. 85 Among other German strainers I mention the "Ditt- mann's," which . consists of not less than 0 pieces, including four metal strainers and two "cushions" of a sort of felting. This has at least the merit of being possible to clean, as it can be taken to pieces. But as said before, prevention is bet- ter than cure, and no amount of straining will purify milk if pail after pail is poured on top of the dirt, and it may be- come a detriment if the strainer is not kept perfectly clean. A piece of flannel is easy to wash and when it felts too much for reasonably quick straining, a new one may be had at a small cost. FILTERING MILK. Among the systems of cleaning milk is the one used, I believe, first by the Copenhagen Milk Supply Co. They had an apparatus where the milk entered at the bottom and passed through a deep layer of sponges laid between perfor- ated plates. The keeping of the sponges clean proved a ter- rible task and later layers of gravel were substituted. A gravel filter designed by Scheller and Schreiber, of Ger- many, is shown in Fig. 81. The milk enters at e through a strainer, passes through the coarse gravel d, and then by the pipe f, through the perforated double bot- tom b in the lower compart- ment; through the fine gravel u to the outlet g. The ap- paratus is drained by the valve at h. Dr. H. Tiemann reports in Milch Zeitung some experiments with this filter, showing that 60 per cent of the original slime and dirt was removed, and that the number of germs in the unfiltered milk varied from 49 to 166 millions in one c. c., and in the filtered milk from 46 to 168 millions, showing but a small improvement from a bacteriological standpoint. The capacity of No. 00 is fully (>00 Ibs. per hour. 8L 86 The gravel is washed in a perforated drum revolving in a trough. C. Bolle, the great milk [man in Berlin (Germany) devised a gravel filter shown in Fig. 82. It consists of a large vessel where the milk enters at A, and passes through three lay- 1 era, B, Bl, B2, of gravel of in- creasing fineness. It is claimed to treat 2,400 to 3,000 fibs, per hour and to reduce the number of bacteria from one-third to one-half. The gravel is washed with boiling water, then with muriatic acid and then again with boiling water until all trace of acid is removed. Dr. Backhaus uses cellulose in a mush-like shape as filtering Fig. 82. material. In Fig. 83 is shown the International Filter (Chicago) in position for operation. It consists of two perforated plates with layers of flannel or felting between, all en- closed in a cast iron casing, which can easily be opened. The milk has to have some pres- sure, and hence the milk vat is placed on the floor above from whence it enters the filter under the lower perforated plate, passes through the felting and from there into milk bottling tank. This filter seems to me the simplest possible and Fig S3 only the high price is an excuse for its not being used more extensively. * 87 CLEANING MILK BY CENTRIFUGAL FORCE. But what is the use of all these elaborate devices, with the daily cleaning of pipes, etc., when we have in the separa- tor a device easy to clean and perfect in action, the only draw- back being the power required. When creaming milk by centrifugal force was intro- duced it wras soon discovered that even the most carefully strained milk would leave a layer of sediment on the walls of the bowl. As this consisted of fine dirt and dung and scales which had passed the sieve and also fine bits of mem- brane from the milk, as well as bacteria adhering, the thought of purifying milk by centrifugal force lay near. F. Ludloff, of Berlin, (Germany) and others have made special Fig. 85. Fig. 84. separators for this use, and Prols. Dunbar and Kister describe in Milch Zeitung, 1813!), a separator constructed like those used in laundries with perforated bowls, Fig. 84. These bowls are lined with fine strainer cloth and the milk forced through by centrifugal force, as shown by the arrows, and this is in reality nothing but a filter, like the International filter, only the pressure employed is greater and in spite of this, the cloths will soon be clogged and have to be renewred. Far better is the Heines milk cleaning separator, Fig. 85. The milk enters the bowl at a and the separation of the heavier dirt commences at b, and it gathers on the wall of the revolving drum, C C. The milk passes out of the separator through the filter cloth d, whereby any lighter foreign sub- stance is retained. The drum is large and revolves only 1.000 revolutions per minute, and the capacity is about -,~>00 Ibs. per hour. 88 The milk used was better than the average, varying from 2.5 to 18.5 milligrams dirt per liter, while the milk de- livered in Hamburg market for 1898 varied from 0 to 183.5, with an average of 13.5 milligram per liter. The result of eight tests showed on an average 9.5 milligram dirt in the new milk and 1 in the centrifugated milk. Experience has shown that there is no need of employ- ing specially constructed separators, as those used for skim- ming will do the work satisfactorily; thus Mr. H. B. Gurler uses a No. 3 Alpha De Laval in his sanitary dairy. There has been some fear of difficulty in getting the milk and cream mixed again, but if the two streams are run together and passed at once over a cooler, there will be no trouble. A great advantage of this system is that it puts it in the milk man's power to deliver milk of a guaranteed percentage of fat by either removing part of the skim milk, or, in case of very rich milk, part of the cream. It is true, this system requires power — steam or hand — but it is certainly the very best one for cleaning milk. PRESERVING THE MILK FOR DELIVERY. Having purified the milk by either of these mechanical means, the next step is to secure its preservation. As said before chemical preservatives should never be used — it is ille- gal as well as immoral, and the simplest and best system is cooling it at once as much as possible. FARM COOLERS AND AERATORS. A common system of cooling is to strain the milk into the shipping cans, which are placed in a water tank just out- side the stable, and to rely on the wind mill to keep the water flowing. The milker is then supposed to give the milk a stirring up every time he pours in a pail, either with a dipper or one of the special hand stirrers or aerators of which I illus- trate one in Fig. 86. It is a bell-shaped cup at the end of a rod. In pushing it down through the milk it carries the air down and lets it 89 Fig. 86. escape through fine holes in the top of of the bell. But too often is this stir- ring or aeration neglected, and too often there is no wind mill or no wind, and pumping by hand is too much work. For this reason I am decidedly in favor of uxini/ Iced water. Farmers ought to have a stock of ice any how, as it is a great economy in the household, and if a pond is within reasonable distance it can be laid down for f 1.00 per ton. But even if it were to cost |3.00 per ton it would pay and an ice house can be built very cheaply. I have, in Sweden, pre- served ice in a heap of saw dust, and it may be preserved in a bay of the barn by simply covering with straw, although the loss by melting will be greater than in a properly con- structed ice house. Of ice coolers for use without or with but little water, I illustrate the original McPherson in Fig. 87, where A is like a milk pail with a lot of fine holes at the bottom d and is placed on the ice pail B, which is filled with ice. The milk flows over B, being cooled and aerated and runs from the annular ring b into the pail. Similar coolers made are the "Champion," (Fig. 88), the "Model" and the two made by Sturges, Cornish & Burn Co (of Chicago). The former (Fig. 89) fj*£& § t :n Fig. 89. Fig. 88. 90 is on the plan of the Smith cooler, being made with corruga- tions. The latter has small concentric rings, which tend to delay the milk in its downward course. The upper tank is a good deal smaller in proportion than the original McPher- son. In order to get the full bene- iit of the ice it is necessary to have some kind of device for stirring the ice or keeping the cooling water iii motion. Mr. Brown, in his cream cooler, Fig. 9(H, provides a hand pump. The cream runs in at a and out at the bent tube, which may be lowered to empty the can. In handling milk or cream, pas- teurized or unpasteurized, for the market, too much stress can not be laid on a quick and thor- ough cooling, the nearer 34° the better. Where cold water i s plentiful coolers on the PLawrence w principle, Fig. 9oy2. such as the "Star," Fig. 91, or The Reid (see Fig. OS), and others are among the best of all coolers and aerators combined, and if water is scarce, the best system is to have a water tank filled with crushed ice and circulate that in the cooler. Fig. 91. AERATION. Meanwhile, if the combined coolers ami aerators are not available, cooling by aeration only is better than nothing, although perhaps this may hardly be true when speaking about preparing milk for city shipment. The simplest aeration is by lifting a dipper of milk 91 from the can and let it slowly fall back in a small stream. \ Canadian, Mr. 1*. \V. Strong, of Brockville, Ont., patented this simple and cheap device for aerating. Fig. 93 explains itself. Strain the milk through the bucket, which has a perforated bottom, and if more aeration is needed lower the bucket to the bottom of the ship- ping can, when a valve opens and lets in the milk, which is hoisted up again, and so on. D. H. Burrell, of Little Fig 93 Falls, N. Y., makes the aerator, shown in Fig. 1)2, which explains itself. The bucket has a perforated bottom and the milk is strained into it, falling from there into the can. Mr. Boegild (Denmark) constructed a hollow cylinder over which the milk flows in a very thin film and is cooled by the air which passes through the cylinder. Hundreds of devices for aerating milk have been patented, but most of them depend up- on perforated tin dividing the milk in fine streams as it is poured into the shipping cans, as Fig. 94, the so-called Vermont strainer and aerator, or like those previously described. Others de- pend on blowing the air into the milk like Mr. E. L. Hill, of West Upton, Mass. Fig. 94. 92 Fig. 95. Fig. 95 shows the box with the blower, which is turned by a crank, and the hose connected with the noz- zie, which is placed in the milk can. Provided hose and nozzle are kept clean and absolutely pure air is avail- able, this system does good work. Yet, I consider the combined aerators and coolers are much to prefer. While Danish experiments have lately thrown some doubt on the bene- 11 1 of aerating the milk on the farm near the stable, even if done in a | special room, the Danes have taken up the idea of aerating the hot cream in rather an enthusiastic manner, and several special devices have been put on the market. Thus Konstan- tin Hansen & Schroeder, of Kolding, solves the problem as shown in Fig. 95J. In the usual Smith cooler is placed a tank "a" in the upper part of which a perforated plate "b" is fixed. The cooling water is led through the pipe "c," and forms a fine shower, leaving at "d." The air is forced through this by the pipe "e" and "f •' to the aerating tank "g'? from which it can only escape through the cream shower coming from the upper tank "h" and out by "k," while the cream leaves at "1" for the cooler. It seems to me a very neat way of aerating cream and a desirable one if the cream is tainted with turnip or weedy flavor, but 1 should lay great stress on securing pure air. The air is forced through by a small centrifugal blower running at 1,500 revolutions per minute, and is purified by Fig. 95 J 93 passing through the water shower. It is even suggested to use oxygen for aeration if it can be obtained at a low enough price. The apparatus sells, as shown, for $40 in Denmark. THE MILK PAILS AND SHIPPING CANS. Interesting as it might be to discuss and illustrate the various pails and cans used all over, I shall here confine my- self to draw attention to the importance of buying the best and those with the fewest seams carefully and smoothly sol- dered. There is no more dangerous lurking place for dirt and bacteria than an unevenly soldered seam. A few years ago the "Reform'' can wras introduced in Denmark, shown in Fig. 96. These cans are made of two pieces, pressed out of the very best English steel plate, joined in the middle of the side and heavily tinned. The cover is of one piece and the handles only are riveted. Dairy Counsellor Boeggild strongly recom- mended this can in "Maelkeritidende." The price for the 8-gallon size is $3.00 in Denmark, but if it is durable it would be cheap at $5.00. It seems, however, after some years' experience that the tinning of these cans has not been satisfactory, and yet I hope that as, for instance, Messrs. Sturges, Fig. 96. Cornish and Burn, who are stamping out seamless cheese hoops may take up this idea. It will be seen that the only seam is easily got at and visible, and if the tinning can be made to endure, they should fill the bill. Meanwhile it will pay milk producers to pay a little extra to get pails and cans soldered perfectly smooth and with no sharp corners. Cans when rusty may giye the milk a very disagreeable taste when left over night by a combination of iron, as has been proved in Denmark. Finally it must be remembered that all the previous precautions and cleanliness may be love's labor lost if pails and cans are not cleaned properly and sterilized by steaming or rinsing with boiluuj water. In this connection let me say that if milk shippers knew their own interest and citv dt-al'M-s theirs, no cans would be 94 left standing and returned with a milk rest in them, but they would be rinsed at once with cold water, even if they are not thoroughly cleaned and steamed. It is an outrage to common sense not to do this, as any one, who ever smelled some of the returned cans left to bake in the sun for hours, if not for days, can testify. All utensils used for milk should first be rinsed with cold or lukewarm water, then scrubbed with soda water or some of the more expensive soap powders, never with soap, rinsed again and scalded. Rinsings with soap pow- ders in should not be given to hogs as, according to Bulletin 141, Cornell Experiment Station, it may kill them. There is one style of milk pail against which I must warn the dairymen, especially if they leave sour or partly sour milk in them. I refer to the plan — in order to prevent rust — of soldering a zinc plate on the bottom. German experience has shown that poisonous salts may form and it also makes it harder to keep them clean. PASTEURIZING ON THE FARM. The beauty of the pasteurizing process is that anybody may use it on a small scale without investing any money in special apparatus more than a small thermometer. In Fig. 97 is shown a tin boiler in which a quart and a pint bottle is placed on a perforated loose bottom. This boiler is placed on the stove and the temperature raised to boiling point; when it is left alone for about 30 minutes, as a rule the tempera- ture will not have fallen below 150°, and the bottles are then taken out and cooled. Having tried if the customers like it, and having seen the advantages, which, as before said, are all the greater the nearer the pasteurizing is brought to the* Fig. milking time, there is no need of any expensive apparatus as long as the amount handled does not exceed 50 or 60, aye, even 100 quarts. Get as many shot-gun cans, 8 inches in diameter and 22 95 inches high, holding 40 tbs. each, as may be needed. Place them in aii oblong boiler (Fig. IKS), made to order if necessary. Get a suitable tank for cooling, and a stirrer (see Fig. 98.) That is all there is required. Fig. 98. I acknowledge, however, that if money and steam is at command, it is less work to use some special apparatus than to keep four or five cans stirred by hand, yet part of this gain is counterbalanced by the increased labor in keeping the apparatus clean. Stir the milk continuously until it is 140° or whatever higher temperature that may be decided on, and see to it that when it has reached that temperature the water in the boiler is only a degree or two higher. If it should be higher, reduce it by adding cold water. Place the boiler where the temperature will remain station- ary for '20 to 30 minutes and cover the milk can. Meanwhile, have a tub filled with cold water, preferably with ice water, and place the milk can in it. Moving the can round with one hand (so as to stir the water), the milk is stirred wTith the other hand until at least 50° cold. Where there is a tank with flowing cold water, it is enough to stir the milk, but where neither this nor ice are at hand, the quantity of water must be regulated according to its temperature. If, as for instance, there are 20 Ibs. of milk at 155° that we desire to cool to 60° (50 would be better), we have to cool 20 Ibs. 95° or 1900 units. Supposing then we have water at our command at 48°; then we must theoretically have 158 J Ibs. of this water to reduce the milk to 60°, but practically this is not enough and it would be too slow work, hence I consider that 300 Ibs. of such water would be nearer the mark. The best way of cooling is to run it over one of the small surface coolers in a clean room. This question of cooling is the great stumbling block which for years will prevent farmers from pasteurizing the milk. Indeed, I feel inclined to make the broad assertion that unless there is flowing water of not more than 48° or 96 else a good supply of ice, pasteurizing should not be at- tempted. But, as I have urged again and again, there is no reason why every farmer should not lay in a stock of ice, the theoreti- cal amount required to cool 20 Ibs. 95° would be about 14 Ibs., but practically it will take about pound for pound unless the first cooling is done with water. In that case ^ Ib of ice to 1 Ib. of milk may be figured on. Pasteurizing costs money for fuel to heat and ice to cool, and the latter is the most expensive, but even if we take the highest amount of ice, the cooling will after all only cost 10 cents for 100 Ibs. if the ice is |2.00 per ton. It is an easy matter for anyone who has a thermometer to make the above experiment on a small scale and convince himself of the effect. When pasteurizing in cans for filling in bottles later, it is absolutely necessary to have the bottles sterilized. This is done by placing them (after cleaning, shortly before using) in a boiler with water and bringing it to a boiling point, then let the water cool to about 160°, take out the bottles and cool them, bottom up. Meanwhile several pasteurizing apparatus have been constructed for use on the farm, or where no steam is avail- able, and in Fig. 99 I illustrate the hand pasteurizing heater "LE FRANCAIS" made by Gaulin & Co. (Paris, France). It consists of a lower part, a low pressure boiler provided with safety valve, etc. Above this is the pasteurizing heater proper, the frame work of the stirring apparatus may be re- moved so as to make it easy to- clean. The boiler is filled through the funnel, and the construction is otherwise of the ^ Fjord pattern. It is made to FIg 99" work 250 Ibs., 500 Ibs. and 1,000 Ibs. per hour. The smallest is about 4J feet high, and sells, for about fllO. Fig. 100. Kleemann & Co. (Berlin, Germany) constructed a hand pasteurizing heater shown in Fig. 100. To the left is an iron low pressure boiler (B) connected with the jacket of the heater by a pipe be- low and above, by which a constant cir- culation of the heat- ing water is ob- t a i n e d, heating the milk in the tinned copper vessel A. A hand stirrer is provided to agi- tate the milk. The smallest size holds 100 Ibs. of milk, will heat to 190° and costs about |90. It seems to me that this idea could be modified so as to have shut off cocks on the pipes connected with the heater and water connections for cooling. Creamery Package Mfg. Co. (Chicago), has a farm pasteur- izer similar to the ''Pasteur" for places where no boiler is available. Fig. 101 gives a general idea of it. It consists of a cylinder, in the lower part of which is a fire place for heating the water, in the upper part, where an inner cylinder provided with a hand-stirring de- vice, holds the milk. When heat- ed, the fire is drawn and ice water is circulated between the two cyl- inders from an overhead tank. It is made in sizes of 10 gab, 20 gal. and 40 gals. This firm also sells a vertical tank pasteurizer devised by Nelson, and a continuous one, the Ideal, which seems to be like the original Fjord. 98 It will thus be seen that there is no excuse for the in- dividual milk producers and dealers to neglect taking up this question right away, but I shall now outline my ideas of the proper system of the city milk supply. OOOPERAJllVE MILK SHIPPING CREAMERIES. I Lead this "CO-OPERATIVE" because it is my firm be- lief that ultimately the farmers will have to learn true co- operation if they are to hold up their end in these days of "expansive" trusts. But the system which I shall outline shortly may be established — indeed it is established partly in some states — by the large city milk dealers. I refer to milk shipping creameries. It is absurd waste to ship a sur- plus of milk to the cities, and make it into butter unless in- deed there is a market for fresh buttermilk at fancy prices. When this was tried in Chicago the freight amounted to about 6 cents per pound of butter. With a complete system of shipping stations and especially if the milk is pasteurized or frozen, or both, there is no need of having any surplus. No milk should be accepted for pasteurizing or shipping which shows more than the Fairing-ton limit of 0.2 per cent acidity or lice by the Mann's acid test, but I feel inclined even to reduce this to 9 cc by the Mann's. I hope to see co-operation introduced among the farmers in each district and the building of permanent buildings, if not so elegant, at least as sanitary, as the German creamery illustrated on page 77. I want to see the city milk paid by the Babcock as well as that sold for butter and cheesemak- ing purposes. I wrant to see these milk shipping creameries fitted out with separators for cream raising and milk clean- ing purposes, with continuous pasteurizing outfits on the line suggested by me in the first edition of this pamphlet and illus- trated in Mr. A. H. Reid's (Philadelphia) pasteurizing outfit, Fig. 102, The milk is elevated by the pasteuriz- ing heater to a milk tank with partitions which compel the milk to go zig zag to the cooler. Or, if preferred, a system of three storage tanks could be used for the hot milk, each tank holding one-third of the hourly capacity of the heater and cooler. Of course, those who prefer tank pasteurizers may use the Potts or similar ones, but I strongly recommend the sudden chilling by using surface heaters, even if covered. I want to see a good Re- 99 Fig-. 102. frigerator Machine and a good stock of ice put in. I want to see a complete bottling outfit and arrange- Flg. 103. 100 ments with the railroads to fit cars with racks for the bottle boxes so that the freight may be kept down to about the same price as for milk in cans. If such creamery shipping stations were made the gateways for all milk sent to the cities, the farmers could get their milk paid by the test and they would not need to get up in the middle of the night because with pasteurization or with freezing, or with both combined, it would matter but little whether the milk was shipped early or late, and the milk dealers would have no surplus waste. In this bottling outfit there should be the very latest and best bottle washers. I illustrate the "Ideal Turbine" in Fig. 103. It is sold by Creamery Package Mfgf. Co. (Chicago). It consists of a tank with two compart- ments. Behind the one to the left H is a turbine bottle brush A. and in the back of the other F is a bottle rack in which the bottles are inverted over the 24 spray pipes E through which cold or hot water or steam may be applied by an automatic foot lever I. Cold water comes through C. Steam through B and at X there is a steam jet. Smaller- tanks with a bottle washing brush rotated either by steam, belt or foot power are also in the market. The latter is illus- trated in Fig. 104. The operator stands on the opposite side of the tank and revolves the crank with his foot. Tank holding about seventy quart bottles and cleaner complete cost only $10.00. Fig. 104. STERILIZING OVENS. While it may be possible to keep bottles clean with water, there is hardly any reason why every farmer with ten or 101 more cows should not have a so-called feed cooker so as to produce steam, even at a low pressure, and thus have the means of properly cleaning his cans and dairy utensils. They are sold cheap enough, varying from $35 to $75, and are as a rule, built in America, like a vertical boiler. SIP Fig. 105. I said a very low pressure would do, yet if perfect steriliza- tion is to be obtained, there should be a pressure of not less than twenty Ibs. and great boiler like ovens have been built for sterilizing bottles, but as far as I can learn there is an objection to the high heat which seems to act on the glass and keeps it "cloudy" so that bottles are not bright. Further- more low pressure steam should be all sufficient. Prof. Russell suggested a galvanized iron box (Fig. 105) taken from Wisconsin bulletin. There is a square box made of galvanized iron with a door and a vent for the escape of steam V. The steam enters at St. P through a pipe provided with a dropcock C, and with four openings ST. PV with pipes P inserted, and one SV opening into the upper part of the box. There are two shelves WS of wire netting, and the lower space is .used for cans placed directly over the steam pipes P, while the upper shelf is used for bottles, covers, etc. This and similar boxes are made in any size or styles to suit, by 102 manufacturers of dairy supplies and machinery. Mr. H. B. Gurler built a steam-tight, cement-plastered room, into which he rolls the large bottle racks. Whatever system is used, boiling in water, steaming in the open or in closets, it is all important to submit the bot- tles, cans, etc., to a temperature of about 212° or more for ten to twenty minutes if the whole pasteurizing process shall not be a delusion and a snare. Indeed I believe if we had to give up either it would be better to give up pasteurizing than sterilizing the cans or bottles. THE BOTTLES. Fig. 106. Fig. 108. There are many milk bottles in the market, with all kinds of patent tin covers and closing devices. In Fig. 106 I illustrate some bottles used in France. Lately, however, the "Common Sense" milk bottle, Fig. 108, or its imitation, the "Ideal," is absolutely gaining the ground, and wherever they can be transported "right side" up, they are, undoubtedly, the simplest and easiest to keep clean. The paper cap is renewed each time, and there is no wire or tin to be in the way of cleaning. The cap is made of paraffined paper, and as a rule fits so well as to allow the bottle to be held upside down without spilling a drop. It is indeed claimed that they may be submerged in water with safety, and there is no trouble at all if they are handled in cases like Fig. 109. For shipping and delivering are used wooden boxes with partitions for twelve bottles and if desired they are made 103 like Fij^. KM), with a removable galvanized iron lining. The niilk can be iced down and the case closed, thus serving as a perfect refrigerator at all times with no fear of water drip- ping from the case when the ice nielrs. And for delivering from wagon, a wire1 basket, like Fig. 110, is often used. Fig. 109. Fig. 110. BOTTLING AND SEALING. Various bottling devices have been put on the market, more or less complicated and difficult to keep clean. If only a limited number of bottles ar" to be iilled a jug with a glass funnel, the stem of which reaches nearly to the bottom of the bottle, placed so that it does not prevent the escape of air, is the simplest. But small fillers can also be had from the dealers. The Childs filler is the one most used and known and I shall here only illustrate the UP-TO-DATE bottle filler, the latest de- vice sold by Creamery Package Mfg. Co., in Fig. 111. The bottles are push- ed into position four at a time by a bar and by press- ing a foot lever they are raised up against the valves, which open auto- matically, while a rubber cushion prevents any over- flow. The milk is sprayed against the walls of the bottle, while the air es- capes through the air tube Fig. in. in the center of the valve. 104 These are also made with a rotary stand and a capping de- vice. I have not had reports of its work, but it seems prom- ising to me and well worth investigation. One of the greatest problems which meet dealers in plac- ing sanitary (certified) milk on the market is the danger of dishonest agents and customers' servants tam- pering with the milk. The Common Sense bottle having no wrire fasten- ings which might be sealed, Mr. H. B. Gurler planned a special cap to cover the paper one, Fig. 112, stamped out of tin and sealed with a lead seal, in which the date of filling may be Fig. 112. embossed if so desired. THE CITY MILK DELIVERY. This is one of the most unsatisfactory phases of supply- ing large cities. What terrible economic loss is there sus- tained by having ten or twelve delivery wagons pass over the same route? Here is a case where a large combination would be justified, but I should prefer to see the milk producers have the main say in such a combination. This enormous expense in delivering is not the only drawback. It is true we have in nearly all our cities several large companies who have excellent facil- ities for handling milk in a sanitary manner, but alas, we have also many small, dirty and unsanitary milk depots where there is not even the most primitive attempt at sanita- tion; w7here there is hardly decent facilities for washing the cans and bottles, and when such dealers peddle milk in bot- tles that system is a great farce. Small milk dealers or grocers and bakers who handle only one or two cans of milk ^^^ should never place them in a re- frigerator with other things; far better is it to have a special water tank lined with galvanized iron, as shown in Fig. 113, for two cans where the ice is placed be- tween the two cans which stand on a wooden rack. Right here is the advantage of shipping the milk in bottles generally, such Fig. 113. small dealers could handle the 105 bottles in an ice box or refrigerator or even in the iced ship- ping boxes, and would be compelled to do an honest business without taking extra profit in the shape of one or two quarts of cream from each 32 quart can. The delivery from cans still obtains to a great extent, and if the customers would only keep their receiving can or jug clean, there is, of course, a saving in cost. Yet, many are the difficulties. , In Germany insulated wagons with large cans are used and faucets protrude from the side of the wagons with signs reading: Milk, — per quart; half skim, — per quart; skim, -- per quart; buttermilk, -- per quart. The wagons are locked and thus the honesty of the driver was deemed secure. But alas for human inventiveness! A smart driver had the happy thought to drive round to a quiet alley and apply a force pump connected with the faucet by a rubber « hose, forcing the desired amount of water into the milk to his own profit and his employers dishonor! Later a patent faucet put a stop to this. In England (and Germany, too) a tricycle, Fig. 114, is often used for small routes. A heavy can with faucet is swung on the bear- ings and a basket in front carries the bot- tled milk or cream. Neat wagons are of importance in de- livering milk as wrell as a neat dress on the driver. In fact, I see no reason why he should not have a plain uniform. It costs no more than ordinary clothing, and is certainly attractive. Personal fancy plays, of course, the main part in selecting the style of wagon. and dozens are offered in the market. It seems, however, as if the so-called "low down" wagon, of which I illustrate one in Fig. 115 is gaining favor. The tendency of the cream to rise in the milk cans where the delivery is made from a faucet in large cans Fig- 115- cannot be denied. BUT whether it is a question worth raising unless smooth asphalt streets and very soft springs under the wagons are in evidence may be doubted. In Germany where the delivery is nearly exclusively from faucets, various devices have been used for preventing the cream from rising. Thus Thiel & Sohne (Ger- many) made a wooden floater and suspended sev- E eral chains under this which swing back and forth and thus keep the milk stirred. Others at- tach a perforated tin tube to the faucet (Fig. 11(>) and others again place a per- forated cone wrhich is supposed to let to the faucet milk from all the different layers in the right propor- tion. Koch & Co. (Germany) made a moveable apparatus for the cans shown in Fig. 117. It consists of a tube B with six horizontal plates reaching close to the wall of the can. In the tube are spirally arranged slits. The plates prevent cream from raising and when the faucet is opened a current is started, as shown by the arrows. When in New Orleans (in 1898), I found large cans with faucets used extensively and the milk inspector assured me that he had repeatedly tested the matter and found that there no raising of the cream took place during the deliv- Fig. 116. Fig. 117. 107 ery, and that the last milk tested no richer than the first. In view of the conditions of most of the streets at the time of my visit, I did not feel inclined to doubt the assertion. No doubt there has been too great a fear of this injus- tice to the first milk customers and even in Germany has Jos. Siedel demonstrated that with soft springs under the wagon the difference in the test of the first and last delivery was on a smooth street, 0.4 to 0.5 per cent, and with stiff springs on a similar road there was actually no difference. It is only when the cans are left standing for any length of time that there will be real danger of any injustice. As an example of the better, but unpretentious, city milk delivery under the present system, I shortly describe that of Sidney Wanzer & Sons, Chicago. The front part is any- thing but imposing and the retail shop might be made more attractive, but the Wanzers have built up their business during the past forty years and preferred to put the money in the essential part, the milk rooms, etc. The new build- ing is solid, with cement floors of the best description. AY hen the milk comes in about 100 out of the 150 cans are selected • and lifted on a platform and poured in a small receiving tank and some labor could be saved here by one of the English can elevators shown in Fig. 75. From this tank the milk runs through a Miller pasteurizing battery, consisting of one heater, one cooler for city water and one cooler for brine circulation. It is thus heated to about 158° and cooled to 50°, passing from there through an International filter, (see Fig. 83) to the bottling tank. A Childs bottle filler is used. The bottles are then placed in the boxes and stored in the refrigerator ready for delivery. A refrigerator machine fur- nishes the brine at from 16 to 28°, and a liberal supply of ice is at hand. There is no taking of a quart or two of cream, as most of it is bottled and sold as it is. -SANITARY DAIRIES"— "CERTIFIED MILK.' \Yhile pasteurizing undoubtedly is of much benefit to the great masses of consumers as well as to the producers and dealers, we cannot refuse the verdict of the great ma.joriiy of physicians that strictly sanitary milk is better, but how many consumers can afford to pay from ten to twelve cents per quart? And it is no especial money making proposition 108 | View of H. B. GURLER'S Stable, DeKalb, 111. to produce and deliver it in the proper manner at that price. So-called sanitary dairies must fulfill the following condi- tions to be entitled to the name and to the endorsement of physicians. 1. The cows must be tuberculin tested and inspected regularly by a veterinarian; surgeon to be sure of their per- fect health. 2. The stables must have plenty of light and good ventil- ation and have cement floors, walls and ceiling must be smooth and should be white washed once a month or there about. The drainage must be perfect and so must the sur- roundings. System of tying should be comfortable for the cows. 3. Cleaning of the stable should be done often and thor- oughly, and the cows should be kept groomed like race horses. Both of these operations should not be undertaken within thirty or sixty minutes of milking so that time will be i^iven for the dust raised to settle, 4. Milking should be done as aptly described in Mr. H. B. Gurler's circular: ''One-half hour before milking the 109 cows are groomed. The milkers are required to clean their hands and put on white milking suits. I have one man to clean the udders of the cows just in advance of milk- ing, using a sponge and warm water for this purpose. I -form- erly required each milker to clean the udders of the cows that he was to milk before he commenced to milk, but learned ill ' manipulation of the udder stimulated the secretion of milk and, if the milking did not immediately follow, that the re- sults were unsatisfactory. We must work with nature to secure the best results. I secure better results from the cows when the milking follows closely after the cleans- ing of the udders. Each milk pail is furnished with a closely fitting strainer cover, into which is fastened a layer of absorbent cotton, so that all the milk passes through this cotton before entering the milk pail. The milk is poured out through a covered spout so the strainer is not removed from the pail until through milking, when it is destroyed and a new one is prepared for each milking. The milk pails, strainers, cans and all utensils used about, also the bottles in which the milk is shipped to the consumer, are thoroughly cleansed and then sterilized by live steam in a sealed room, the temperature of which is held at 212° Fah., for thirty min- utes. The first milk from each teat is rejected as experience has shown that germs which sour the milk invade these pas- sages and cannot be gotten rid of by the washing process." 5. The feed should be sound, varied and fairly balanced. The water should be absolutely pure and not ice cold. 6. The milk should also be treated on a similar plan as obtaining on Mr. Gurler's farm, where both ice and refriger- ator machine is available, the latter not being indispensable if only a large enough tank of ice water is prepared in time. "As soon as the milk is obtained it is run through a centrifugal machine, such as has been in use for some years in creameries, as a means of rapidly and economically sep- arating the cream from the milk. I employ it for the pur- pose of holding the milk at a constant per cent of fat and at the same time separating from the milk any dirt or other solid matter which may have gotten into the milk in spite of the precautions previously used. Although in this opera- tion the cream and milk are separated from each other, they are again mixed when they come from the separator and 110 there is left behind in the machine a peculiar mass of mucus, germs, etc., which it is very desirable to have out of the milk. Immediately after leaving the separator it is cooled to a low temperature. This low temperature secured very quickly after milking is found to be very desirable as it im- proves the flavor and keeping quality of the milk. The milk is then bottled, each bottle stoppered with a wood pulp stopper, and a metal cap and seal put over the top in such a manner that the contained milk cannot be reached unless the seal is destroyed. On each seal is stamped the date of the bottling and rny signature. This seal is a guarantee of gen- uineness to the consumer. Although this process seems complex, it is in reality carried out quite readily by the trained workmen in my employ." The above mentioned seal is illustrated in Fig. 112. The bottles are shipped and delivered to customers in boxes filled with crushed ice. "An eastern bottling room/' from Major H. Alvord's bulletin No. 29, U. S. Agricultural Department. A MILKING PAKLOK. The following proposal made by Mr. J. D. Frederiksen, of Little Falls, N. Y., manager of Chr. Hansen's Lab-oratory, Ill is not so very Utopian and deserves a serious consideration by students of the problem, how to secure a sanitary milk supply: "In handling and preserving milk, measures calculated to prevent contamination are innuitely better than remedies for defects allowed to develop in the milk at an early stage. Whether .cooling or pasteurization or both are applied for its preservation, these means should be used while the milk is as iresh and pure as possible. A friend of mine in Denmark who has devoted a large part of his life to the supply of the city of Copenhagen with pure milk and who is a confirmed opponent to pasteurization, recently told me that in his opinion intense cooling is the only proper means of preserving milk. ''Cooling," he said, "checks any growth of deleterious bacteria, and I would have it applied before the germs have any chance of developing. I would milk into a pail in which the milk strikes a surface cooled by ice direct as it flows from the cow." At a meeting of milkmen, farmers and physicians in New York last winter where the question was discussed what could be done to improve the sanitary condition of the milk supply, some of the health authorities demanded largely in- creased cleanliness in the barn, etc. A farmer, in despair at the exactions required, exclaimed: "Gentlemen, I would milk miy cows in my parlor if I could get paid for it." Now, these suggestions are neither ridiculous nor Uto- pian, but are measures which will be required and carried through, sooner or later, and the sooner the better. In Farmers' Bulletin No. 63, 1897, issued by the United States Department of Agriculture, Dr. R. A. Pearson, As- sistant Chief of the Dairy Division, in his admirable treatise on "Care of Milk on the Farm," shows how the milk is con- taminated in the barn, how the bacteria adhering to dust, hair and other impurities enter the milk and develop with fearful rapidity and how in many cases this is the chief source of contamination. The very measures taken by the careful dairyman to keep the cows and the stable clean are apt to defeat their purpose. Just before milking, the drop- pings are raked dowrn from under the cows, the bedding is shaken up, and the cows are groomed, all of which tends to fill the air with germ-carrying dust which settles in the milk during the milking, and the mischief is done which the great- 112 est care in cooling and pasteurizing afterward can only partly undo or remedy. To prevent this I would "milk in the parlor." Not in the farmer's wife's parlor with carpet and curtains for dust and bacteria to stick to. But close to the stable I would have a small, separate room in which to milk, a trifle larger than a good-sized stall for each cow to be milked at one time. Before all, this room should be clean; floor, walls and ceiling washed and whitewashed every little while. I would have it conveniently arranged, comfortably heated in winter, a door at one end where the cow enters and another at the other end through which she passes out. A walk with guide-railing should lead to and from the milking room. After a few days the cows would know the way and, as soon as re- leased, would walk into the milking room, and, after milking, out again to find their stalls in the stable. Immediately after milking each cow the milk should be poured through a fun- nel on the wall of the milking room whence it would run out- side over an aerator and cooler (with ice) into the milk can. Or, preferably, 1 would build the milking room on the second story or sufficiently elevated so as to milk into a funnel whence the milk would run directly over the aerator and cooler into the can on the wagon outside or in a driveway next to the stable. In this way the utmost cleanliness and absence of^ unde- sirable bacteria can be secured. The cow can be brushed before milking and her sides and bag wiped with a damp cloth so that she will carry no flying dust into the milking room. Provided there are more than one man to do the chores the milker does not need to leave the milking room and can keep himself absolutely clean, the room being furnished with soap and water. Of course I anticipate objections to this plan; there al- ways are to any innovation. In the first place it will be ob- jected that it would cost too much to provide a separate milk- ing room. Many new stables, however, are being built with a view of securing good sanitary conditions, and the additional expense of a separate milking room can easily be saved by making the rest of the stable less elaborate. For, when the cows are milked in their stalls, the whole stable must be much cleaner than where the milking is done in a separate room. Not that I would reduce the efforts for cleanliness 113 in the stable itself. But the milking room may be quite small, and in most barns a convenient corner can easily be found to partition off for the purpose, or a small, plain room can be built as an addition at a moderate expense. Next it will be objected that it will take too much time to release the cows, lead them to the milking room and back again to their stalls. If everything is conveniently arranged it will take but little more time than milking in the old way. Take as an example a herd of ten cows attended by the farmer and his grown boy. Their present order of business is i his: First they will clean the floor under the cows, rake out the droppings and shake up the bedding; next they will curry and brush the cows and wipe their flanks and udders with a damp cloth. Then they will start the milking. After milk- ing each cow, the milk is carried out of the barn and poured over the aerator. Now consider the new way: The farmer tirst looks to his milking room that it is perfectly fresh and clean, fills the cooler with ice and adjusts the conductors to carry the milk from the funnel over the aerator and cooler. In the meantime the boy has been busy in the stable cleaning and brushing. He has groomed and released the first cow which is now waiting outside the door to the milking room ready to be admitted. After being milked she passes out and the next one which has now been cleaned and is waiting out- side, enters. The first cow finds her stall and fastens herself or is fastened by the boy. A week's training will be ample to teach the cows this routine, and the whole proceeding will work smoothly, hardly taking any more time whatever than the old way. I do not speak of the old way where nothing whatever is done for cleanliness, but I take it for granted that efforts are made to produce healthful and clean milk, and, if such is the case, I claim that the work can be done in the same or but little additional time with a separate milking room, the only difference being that while formerly both hands first did the cleaning and grooming and afterwards the milking, now one attends to the cleaning, releasing and fast- ening of the cows while the other milks. But even if it does take more time and expense, it has got to be done all the same. Health authorities ar clamoring for better sanitation, and consumers are willing to pay for it. Besides, there is plenty of room for improvements in the city —8 114 milk supply by which economy may be practiced so a& to al- low the farmers a sufficiently higher price to enable them to introduce a better system, without raising the price to the con- sumers. Granted that the consumers are willing to pay 8 cents .per quart for sanitary milk, the distributors can afford to pay 4 cents on the platform at the city end of the railroad, which would leave ample margin for the farmers to make the im- provements suggested. Four cents is plenty to pay for the •distribution. Let the distributers combine so as to have one wagon attend to certain streets where heretofore three or five have scrambled for the business. This item of saving alone is more than sufficient to allow for the improvements at the barn. Or, still better, let the farmers combine and take tho distribution into their own hands. In this brief article, however, I shall not attempt to go further into this matter. Suffice it here to say that from any point of view, practical or economical, there can be no serious objection to the above suggestions, viz.: to "milk in the parlor" and to let the milk flow directly from the cow over a cooler, at once reducing the temperature to near the freezing point. And there can be no question but that this would be an enormous step in advance for the production of sani- tary milk for the city supply." J. D. FREDERIKSEN. Little Falls, N. Y., June 1, 1901. I am not expecting the average milk producer to attain these high standards, but even one cent extra per quart will enable the farmer to take some of the most important steps towards sanitary milk so as to enable the milk shipping cream- eries to get the full benefit of pasteurizing or freezing. A HINT FOR CITY CONTROL. Two-thirds of the milk sold is sold by tickets and the cus- tomers seldom see the peddlers. Compel them to print on these tickets whether the milk is new, skimmed- or half skimmed (if the latter grade is allowed). Or — better still- let them print the minimum percentage of fat which they will guarantee. nr> CHAPTER VI.— APPENDIX. PASTEURIZING OR STERILIZING AT HOME. Although I have explained the necessity of getting this work as near milking time as possible, there are conditions where people with a baby might desire to thus treat the milk after buying it in the city. Yet this should only be done ac- cording to the advice of the doctor, because some times it may be better to use unpasteurized milk. It is true late experi- ments in Italy seem to indicate that we have laid too much stress on the supposed decrease in digestibility and it is also true that for the great masses who cannot afford to pay fancy prices (10 or 12c per quart) for so-called sanitary milk, which in reality simply means clean milk from healthy cows, the safe- guard of sterilizing or pasteurizing should not be neglected by the careful mother. Arnold's Family Sterilizer or Pasteurizer is shown in Fig. 118, is recommended by many physicians and is especially adapted for hand- ling small bottles. If the hood is left on, a temperature of 212° may be obtained, while for heating to 150 or 170° it may be left off. It may be bought from dealers in dairy and milk men's supplies or from druggists. City people who do not know whence their milk comes may not even find pasteurizing sufficient and Dr. A. Stutzer in his pamphlet on children's milk recommends the following additional pre- caution : Fig. 118. 116 It consists simply of a strong test tube of same diameter as the neck of the bottle and a short piece of rubber which fits tightly on both, with a pinch cock between. When the milk is filled in the bottle, the rubber and tube is adjusted and the bottle turned upside down as shown in Fig. 119. A few hours' rest will allow any possible dust or sediment to settle in the test tube, the pinch cock is closed, the bottle raised and the test tube re- moved. Fig. 119. MODIFIED OE HUMANIZED MILK. The composition of human milk varies from that of the cow, and in these days but too often has to be substituted. " Koenig " gives the averages of 107 analyses of human and 793 of cow's milk as being: Water Fat Casein & Albumen Milk Sugar Ash Specific gravity Human 87 41 3 78 2 29 6 21 0 31 1 0270 Cow's 87.17 3 69 3 55 4 88 0 71 1 0316 The object of modifying the cow's milk is to bring it as near as possible to the human milk. In most large cities this is done in milk laboratories like Gordon Walker's, and many are the systems for doing this work. Modified milk should always be "prescribed" by a physi- cian, and this is not the place to go nearer into it; hence, I only describe one system which seems to me the most practi- cal, namely that of Prof. Gaertner (Germany). Cool the milk at once after milking it; test it for fat and di- lute it with an equal volume of boiled water. Run the mixture 117 through a separator so that the skim milk contains the added water and part of the original water in the milk, so that the liquid coming from the cream spout has a higher percentage of fat, oy rather as near as possible that of human milk. But if the percentage of fat is increased that of the casein is de- creased to nearly half, as it is mixed with the added water and goes away with the skim milk. Add about 20 to 25 gram milk sugar to 1 litre and sterilize. The result with this modification has been very good in the hospitals of Vienna. But the professors want the milk treated within an hour after it is drawn from the cow, and that it be consumed within 24 hours after it is prepared. The following system in preparing milk for babies, using quite small bottles of only 4 or 6 ounces, was used in the Straus plant (New York). They have a copper cylinder a little larger in diameter than the bottles. The bottles with milk are placed in these cylinders which are filled with water so as to form a cushion and prevent scorching when heating, and bursting when cooling. After they are heated for half an hour the bottles are corked and the cylinders placed in ice water to cool. They gave two formulae for infant's milk. I. II. Sugar of milk. . . .12 ounces Milk 1 gallon Lime water . . . One-half pint Barley water 1 gallon Filtered water with the White sugar . . . . 10 ounces above to make ... 1 gallon Table salt . One-fourth ounce Milk . . 1 gallon These are mixed, filled in the bottles and pasteurized. I give them only as an example, but advise in each case to con- sult the doctor in the matter. TESTING MILK FOB BUTTER FAT. That milk sold for city supply ought to be sold according to test is so self-evident that no arguments are needed, and the simplest of all tests— the "BABCOCK," is so well known that it will only be illustrated by Fig. 120— The "OMEGA" 118 Fig. 120. —made by A. H. Barber Mfg. Co. (Chicago) as a reminder to those who know about it, but do not use it as yet. The "IDEAL," the "FACILE,"— indeed, nearly all the modern power testers are now satisfactory. The whole question of Milk Testing is so well covered by Profs. Farrington and Woll, in their book "Testing Milk and Its Products," that it would be absurd to go into de- tails here. I have before referred to the advantage, aye of the neces- sity, of testing the individual cows if we want to get milk pro- duction on a solid business base, and also suggested the Danish plan of neighboring farmers co-operating and having a young man to do the work by visiting each farm and do the testing there. It is true that another plan would be to have him bring the samples to the creamery and do the testing there if the creamery manager has the good sense to co-operate with his patrons and help in the good work. In the former case the young man (or old one for all that) should have a convenient hand tester, easy to carry from place to place. When the test first came out I had Mr. D. H. Roe put up one of his four bottle testers for me in a telescope case. This was 16^ inches square and 10 inches wide, and there was a special rack for the glassware in the tester. But even this was not very convenient and the modern styles are all made much heavier so that this plan is not practical. The Illinois State Food Commissioner felt the need of a handy traveling outfit for the inspectors to use, and the State An- alyst, Dr. E. N. Eaton, has just got up a modified Babcock Tester, with modified Sharpies "Russian" bottles. This is shown in Fig. 121, and Dr. Eaton thus describes his portable milk tester : "The bottle consists of two parts — the bottle proper and the removable reading tube. The bottle is four inches long by one in diameter, and is divided into two compartments, the lower willi a capacity of about l.Vr for holding ii,(. mjij- ail(j acid, and the top with a capacity of about 40cc for holding hot water to he used to elevate and keep fluid the hm-i of fat. "The reading tube terminates in an inverted funnel so fitting into the top part of the bottle by means of a trap to Fig. 121. allow water to pass through, but effectually prevent the loss of fat. The tube is divided into sixty parts, each part repre- senting one- tenth per cent fat with the zero mark at the top. "The illustration sufficiently shows construction of work- ing parts. The maximum speed is about 2,000 revolutions per minute, and the working speed 1,500 per minute, attained by 60 revolutions of handle per minute. The crank is remov- able. A substantial and handsome mahogany box with handle is fastened by means of hooks. The entire machine boxed occupies 8x8x9 inches. "In the box may be carried tw?o 100 cc bottles of acid (40 tests), a combined milk and acid pipette, a lactometer and thermometer. 120 DIRECTIONS FOR OPERATING. "Measure five cubic centimeters of milk to be tested with milk pipette and allow to flow into bulb of bottle. In- troduce an equal measure of sulphuric acid, Sp. Gr. 1.82-1.83, or that commonly supplied for Babcock test. Rotate with slight up and down motion to thoroughly mix acid and milk. Without delay place in machine, properly balanced and whirl at about 1,500 revolutions per minute (60 turns of handle) for three minutes. Introduce reading tube and nil to within a fraction of an inch of top with very hot water. Whirl for one to two minutes. "The top of the column of fat should be at or a few tenths below O mark on scale. In reading deduct the amount below zero, if any, from the observed reading on the bottom of the column of fat, which gives the percentage of fat to one-tenth of one per cent. "The reading tube may be inserted before first whirling; read "over all" as in Babcock. "When a number of bottles are to be tested introduce milk in all; then acid, and finally mix and whirl. "Keep bottles and tube clean, the latter by washing in alkali or soap solution after forcing water through or by swab- bing with cotton. A stiff iron or copper wire makes a good ram rod!" THE ACIDITY OF MILK. Again the reader is reminded of the fact that the nearer we bring pasteurization (or cooling) to the time of milking the better it is, and if a certain amount of acidity has devel- oped the work is useless. Prof. Farrington places the limit of acidity in milk to be pasteurized at 0.2 per cent (or 11° with the Mann's Test). Milk will seldom taste or smell sour before there is 0.3 or 0.35per cent acid. "Milk Testing," by Profs. Farrington and Woll. It is therefore essential to use some test for the acidity, but I shall only illustrate the Mann's Acid Test in Fig. 122. 121 It consists of a graduated burette with a .pinch cock, a 50 cc pipette, a glass tum- bler and a glass rod. The test depends on the property of a certain chemical called phenolpthalein, labelled "indi- cator," which, while white when in acid solution, turns pink in an alkaline solu- tion. Fifty cubic centimeters of milk are measured into the tumbler with the pipette and four or five drops of the indicator added. Meanwhile an alka- line solution (called neutralizer) (1-10 normal) is filled into the burette to the O mark and then run into the milk, a little at a time, while stirring until the pink color shows permanently. The number of cubic centimeters normal used is read off on the burette and in- dicates the acidity. Prof. Farrington adapted the dry alkaline tablets colored red and a very simple and quick system for testing the milk at the weigh can in order to reject that which is too sour. Full descrip- tion is given in his book on "Milk Test- Fis' 122- ing," which should be found in every creamery and every milk shipping station,— just as Prof. Russell's Dairy Bacteriology should be found in the library of every milk producer. The Chr. Hansen's Laboratory, of Little Falls, N. Y., sug- gested in their direction for use of their Lactic Ferment to use lime water as a neutralizer, and it seems to be approved of by the Scandinavian scientists. It has certainly a great many advantages both as to convenience and costs. The "Neutral- izer" sold for Mann's test, even if correct, when made is liable to lose strength by exposure to air (like all others), and hence it will not do to buy it in large quantities, and the express increases the cost very much. If lime water is fairly reliable there is no reason why every creamery or milk shipping sta- tion manager should not prepare their own. Dr. E. N. Eaton, whose opinion I have asked, reports: "USE OF LIME WATER AS A STANDARD SOLUTION IN TESTING THE ACIDITY OF MILK AND CREAM." It was observed as long ago as 1877 that acidity and ripe- ness of cream bore a definite relation. The relation of sour- ness of milk to its marketability is as old as the centuries, but ip creating more commercial attention since the discovery of the necessity of using perfectly fresh milk for pasteurisation. For thi;- purpose a test even more delicate than the sense of taste is required. Fleischmann & Sebelien, in the old world, and Mann, in America, introduced the chemical method of titrating cream with standard alkali, using phenolphthalein for indicator. A modification of the same method is in common use for testing the acidity of milk. The alkalies almost universally used have been deci-uormal solutions cf sodium or potassium hydrate. Farrington has introduced the alkali in tablet form. Wallace, the Chr. Hansen Laboratory, and probably others, have suggested lime water, and this alkali is now quite generally used in Denmark and Sweden. According to Richmond, Storch uses a solution of lime (limp water) containing solid lime, as it remains constant in composition and is almost exactly twentieth normal. The strength of the solution remains constant as if any of the lime is removed by carbon di-oxide more is dissolved. Its strength •s but little affected by climatical variation of temperature. I am indebted to Mr. Monrad for the account of the fol- lowing method of preparation which is probably that in use in Denmark and Sweden. uThe lime is dissolved in a bottle carefully shaken and then left to settle again. In this way is obtained a solution which, by a reasonably uniform tern perrture will keep unchanged for several months." Dr. E. Holm prepared two samples in this way which were E. Holm prepared two samples in this way which were titrated from time to time at different temperatures and showed quite close agreement. Only slight variation was shown at different temperatures. Thus using 20 CC lime water, — one sample gave the following result: 123 At 18. °C 9.75 C C deci normal H Cl. 15.6 9.85 23. 9.70 22. 9.65 22. 9.62 15.5 9.90 17.5 9.90 This expressed in gms. of CaO per 100 CC equals, for the strongest solution (9.90) .1386, and for the weakest (9.62), .1347. The average strength would be about (9.75), .1366, all some- what less than one-twentieth normal solutions (containing .1400 CaO per 100 CC.) It may be noticed that while in a general way the strength of solution decreases with the degree of heat there is no uni- form variation, a temperature of 23 holding about as much lime in solution as a temperature of 18. The results are, on the whole, very favorable to the use of lime water as a stand- ard for practical work. Lime water has several advantages for use as a standard solution if it can be prepared practically: 1st. It forms a weak solution of alkali which keeps in any climate. 2d. Contamination with carbon dioxide is immediately apparent by formation of calcium carbonate insoluble in water, whereas the alkali carbonates are soluble. 3d. It reacts exceedingly sensitively with phenolphthal- ein, much more sensitive than ammonia with the same indica- tor. In titration of milk products, it has advantages over other alkalies due to the presence in milk of acid phosphates of cal- cium and carbon dioxide 4th, and most important, it offers an opportunity through the limited solution of CaO to prepare and standardize a solu- tion, without the aid of a chemical balance. If the statement of Storch holds good it also reinforces itself to make up for absorption of carbon dioxide from the atmosphere. There is a serious discrepancy in the published reports ot the solubility of TaO in water at different temperatures. Some work has lately been done in this direction and a sum- mary up to date of the solubility at O°, 100°c and between fif- teen and thirty is as follows: 124 Grm>. Ca,O per 100 CO. Temperature. Lamy. A£aber Gunthrie Holm 0 .1381 .1318 10 .1342 .1298 .1342 15 .1299 .1248 .1320 .1386 20 .1264 .1293 .1366 25 .1203 .1254 .1347 30 .1162. .1160 .1219 80 .0734 .0740 100 .0576 .0609 .0597 The lack of uniformity in these results are due: 1st. To difficult solubility of CaO. 2d. To supersaturation or incomplete sedimentation. 3d. To difficulty of filtering and titrating without loss of alkali, due to absorption of carbon dioxide. 4th. To difficulty of holding temperature constant when other than normal. 5th. To impurities in lime. Lamy obtained different results on lime of different origin, although all samples were presumed to be pure, i. e. : were prepared from so-called pure chemicals. In repeating some of this work I obtain the following re- sults, employing pure lime : Temperature. CaO in 100 C. 0. 100 .0602"! 80 .0704 i 80 .0698 }- One determination as high as 79 .0704 | .0625 80 .0*598 J (These results were all on filtered samples and while uniform are probably somewhat low). Seventeen determination at temperatures ranging from 20.5 to 25, some on unfiltered and some on filtered samples gave results from .1123 to .1220. The latter figure obtained on some rapidly filtered samples at the highest temperature is probably nearly correct. The method of preparation was to cool water and lime in refrigerator. Shake well and let stand twelve hours or more to room temperature. Two samples of commercial lime were secured from deal- ers, washed and made up at low temperature and brought to room temperature as before. The results were at first low, 125 and on repeating- the process several times a little high, show- ing incomplete washing. Without recording all the experimental work, it was found that thorough washing by decantation is necessary to remove all free alkali. That just as quick saturation may be secured at ordinary room temperature as by dissolving cold, and that if proper precautions are taken uniform results can be secured at a temperature not exceeding twenty-five and not below twenty-two (71° to 77° Fah). The average of several closely agreeing figures for differ- ent lime, in which the temperature was not the controling ele- ment, gave a solubility of .1265 Gms. per one hundred, or forty- five per cent of and n-10 solution or 10-222 normal solution. Using my results as a criterion Lamy and Maben are too low, probably due to contact with CO2 during filtration as in my work with so-called chemically pure lime, working with comparatively small quantity. Guthrie's results are reason- ably comparable with mine; are the latest results at hand and may be given more credence than older analyses. Holm's are certainly too high, the unwashed lime being probably contam- inated with alkali carbonates. It should also be mentioned that the temperature employed by Holm is much below the usual temperature of working rooms in this climate. My experiments do not justify the assertion that the loss by absorption of CO 2 is immediately corrected by further so- lution of the lime. However, if the contents of the bottle are thoroughly agitated and allowed to stand a day or two saturation is again obtained. As a working method for the preparation of standard lime water, I would advise this procedure: Slack a pound or two of fresh lime in a gallon or larger vessel, by adding double volume water. Fill with water and stir; cover; allow to thoroughly settle and pour off as much clear solution as possible. Repeat three or four times. Trans- fer the fine lime to a large bottle (the larger the better) throw- ing awray any lumps which may be present. Wash again in bottle with ordinary well water, or better, rain water. Fill nearly full and shake at intervals for several hours, at tem- perature between twenty-two and twenty-five degrees C., pre- ferable the latter. Allow to stand at least two days (stop- pered, of course) when it is ready for use. I2f> The clear lime water may be removed with a pipette when wanted, or it may all be transferred to another bottle by means of a syphon. The receiving bottle should be washed with the lime water. The original bottle may be refilled and drawn upon as needed. Tt is absolutely essential that lime water so prepared be kept free from air. Another and probably better method of handling is to at- tach a syphon to the original bottle containing the lime water connected to a burette with two way stop cock. This makes an almost automatic refilling apparatus. A small hole must be placed in the cork, in whicli a tube containing lime may be placed, protected by cotton or cork from too free ingress of air. This, however, is not essential with solution contain- ing solid lime as the CaCOa forms a crust on top which ef- fectually prevents further absorption of C O2. Even in the transferred solution this formation of CaCOs does not per- ceptibly weaken solution if of a depth of eight inches or more. This solution may be used as in the Mann's test, multiplying number of cubic centimeters of lime water used by .45 to get into terms of n-10 alkali. Or recorded results by Mann's test may be divided by this factor to get in terms of lime water, and all results interpreted in terms of C C of lime water rather than n-10 alkali. It will be found more convenient to use 25 CC of cream for test on account of the dilute alkali used. Multiply results by 4 to get in terms of alkalinity per 100 C C. If percentage of acid (calculated as lactic) is desired, con- vert lime water used into CC n-10 alkali per 100 CC of milk, that if 25 CC milk or cream were used, multiply by .45 and 4, and multiply results so obtained by .009. Results, GUIS, lactic acid per 100 CC. A simple method will be, when using 25 CC milk, to mul- tiply cubic centimeters of lime water by 0.0162. If, as for instance, there has been used 12.2 CC lime water, the acid per centage is (with three decimals) 0.198. In ordinary cream- ery work no calculation need be made. E. N. EATOX. TESTING HEATED MILK. In Denmark the compulsory pasteurizing law made it necessary to devise a test, which, if applied to milk cream 127 (or butter), should show whether the minimum temperature of 176° had been applied. Prof. V. Storch devised the following simple test: — A teaspoonful of the milk (cream or whey) to be tested is poured into a test tube and one drop of a solution of hydro- gen superoxide and two drops of a solution of Paraphenylen- diamin is added and the milk shaken. If the milk immediate- ly becomes strongly colored (milk and cream indigo blue, whey violet reddish brown) then it has either not been heated at all or has not been heated over 172°. If the milk assumes a bluish gray color at once or within £ minute, then it has been heated to between 174° and 176°. If sour buttermilk is to be tested half a teaspoonful of clear lime water is mixed well with it before adding the chem- icals, and if a blue color does not show7 it is proof that the milk or cream from which the buttermilk came has not been heated to 176°. Butter is tested by weighing about 25 grams which is melted in a suitable beaker in a water bath of not over 140°. After separating the clear oil, the sediment (brine and butter- milk) is mixed with about an equal quantity of water, and this mixture is treated as before described. The solutions are prepared as follows: 1 gram Para- phenylendiamin is dissolved in 50 grams warm (distilled) water, is filtered through filtering paper and preserved in a broivn glass bottle. It is safest to keep the solution in a cold place. As a rule it will be useless in two months. The com- mercial solution of Hydrogen superoxide is as a rule stronger than needed. If it contains about 1 per cent it may be diluted five times its volume, with water to which has been added 1 cc concentrated sulphuric acid per quart. This diluted solu- tion is also preserved in .brown glass bottles. FILTERED WATER AND LONG KEEPING BUTTER. I have again and again emphasized that the pasteurizing of the cream for buttermakers is only to be recommended. (1) At creameries where, in spite of all precautions, the milk delivered is "off," has weedy or other bad flavors. (2) At creameries where it is known that the butter is to be exported or even held for long cold storage. While there may be ex- 128 ceptions to the last, I am sure that all butter for export should be made from pasteurized cream. Then, and then only, can we hope to work up a reputa- tion for clean, pure flavor, combined with uniformity, which is all important on the world's market. It is not my province here to treat buttermaking, but must emphasize the futility of pasteurizing the cream, if the butter afterwards is washed with any kind of water, a custom which I regret to say obtains generally. If the water supply comes from a deep drive well it may be safely used, but in all cases it would be money well spent for any creamery to have it analyzed chemically and bacter- iologically. Where the water comes from shallow, open wells, or is pumped from creeks or rivers, it should always be boiled or filtered, at least all that is used for rinsing the cream vat, the churn and the butter worker, as W7ell as for washing the but- ter. PASTEUR FILTER. This filter which — I regret to say — requires a pressure of at least 20 HJS. to the square inch to do practical work, and which is rather expensive, is not only a filter, but a complete sterilizing apparatus, as no microbe, no germs of microbes- even, can pass through those wonderful hollow "candles" made of a composition of unglazed porcelain, prepared by Pas- teur's associate, Prof. Chamberlain. The idea of sterilizing milk this way lay near and would obviate the dreaded boiled flavor, but alas and alack, thia filter is so powerful that only a very clear uwhey" would be the result. I have had some correspondence with the company in Dayton, Ohio, and they tell me that a filter for 250 gallons a day, which, I presume, would be enough for the average creamery, if used only for the washing of the butter would cost somewhere about f 100, and this should not prevent their use if they prove otherwise practical. I refer to the trouble of cleaning the "candles" every day. I hope to see this filter given a fair trial. If our experiment stations had taken this matter up in a practical manner, I am sure they would long ago have demon- 120 strated Hia( much of the faulty butter on the market is due to the water. From Mr. Bog-gild's excellent book "Danish Dairying," I take the illustrations Figs. 123 and 124, which represent a galvanized iron filter. The cross section, Fig. 124, shows first a loose perforated wooden bottom, then a layer of pebbles, then gravel, then sand, then an- other perforated bottom. On this there is a layer of charcoal and then a layer of scrap iron. The upper bottom has only one hole in the center, and is covered with pebbles. The height is 3 ft., 6 in., and the filter is filled with the above mentioned materials at least two-thirds. Fig. 123 represents the manner in wThich the filter (a) is fixed on the wall, with the supply pipe (e) and its cock (f) provided with a rod (g). In order always to have filtered water in stock a storage tank (b) is provided. The latter ought, however, to have a cover not shown in the illustration. I am of the opinion that the water, used for washing the butter, ought to be boiled and then cooled, unless indeed the Utopian age were here when every creamery has a pasteur filter. Fig. 124. Fig. 123. as The simplest filter, 1 hough not doing as good work the "Pasteur," is the "International" slio\vn in Fig. s:J, in use for milk. —9 130 A PLEA FOR BETTER BUILDINGS. It cannot be said that very many creameries are built so as to make it possible to keep them clean — bacteriologically clean — or, if you please — dairyologically clean. I know I shall incur the criticism of those men, who, at their own risk, build creameries, so to say, on the suffrage of the farmers. These may at any time see the farmers build one in opposition. Nor do I deny the justice of such criticism, calling my demand for creameries similar to the German one shown as an unpractical, unbusinesslike proposal, when looked at from their standpoint. Yet I shall raise my voice and use my pen as long as I live for better creamery and cheese factory milk shipping stations and city milk depot buildings, and challenge any criticism if made from the standpoint of the permanent interest of the milk producers. There is a great cry against expensive creameries, but that has been because these buildings were not better than the cheap ones, yet the objection alwrays remains against the increased interest on money invested. Let us investigate this question a little. In this country the interest is higher than in Europe, and hence I shall not challenge the claim that we can afford to put up a cheap wrooden building for, let us say $3,000, for a 5,000-fb. cream- ery and rebuild it when rotten for the difference in the interest on a solid brick building costing double the money. I shall not challenge this, I say, though there may be localities where the difference would not be great enough to do it, and though certainly fire insurance ought to be lower in the latter case. But I am not only asking for a brick building, I want it finished somewhat in the style of the illustration. / want a $10,000 building ichere there is now a $3,000 one. The interest account will thus be charged with say 6 per cent on $7,000 extra, or $420. But this will hardly be ] cent per pound of butter. Leaving out the labor saved in keeping such a cream- ery clean, I claim that the simple moral effect on the men working in such a creamery will easily increase the value of the butter } cent per pound. Nor is the claim "theory" but 131 it is based on 20 years close observation of Ihe praHicnl cream- ery-work in many countries. I said that my proposition would be impractical for "in- dividual" creameries, as they are often called, but there is no reason on earth why the farmer should not build such creameries, or the banks lend money in them. Take any community which has been blessed with the revelation of dairy truth, take any bank that has seen mort- gages removed and good accounts opened by the aid of the cow and co-operation, and build such a creamery. Then tell me if it is not sure to make land more valuable in the neigh- borhood, just as does a good school, or a good county building, or a good road. Surely there is no use arguing this point with practical men in this year of 1901. If pasteurization is to be generally adopted we must have better buildings. YOUNG HOUSTON, Prof. Haecker's Ideal Calf. 132 A. H. REID MANUFACTURER OF Creamery Supplies and Dairy Fixtures 30TH AND MARKET STREETS PHILADELPHIA, PA. MOWER-HARWOOD, Cedar Rapids, la. CREAMERY AND DAIRY SUPPLY CO. PASTEURIZING OUTFITS and Milkmen's Supplies Send for Catalogue and Price List before ordering elsewhere 133 EVERYTHING FOR THE Milkman, «£ « Dairyman, Clipper Cooler and tferator. BUTTER OR CHEESE MAKER DAIRY PAILS, MANN'S ACID TEST, MILK BOTTLES AND CAPS, MILK BOTTLE FILLERS. The Best of All. MILK COOLERS, MILK HEATERS, MILK TEST GLASSWARE, SEAHLESS CHEESE HOOPS. BOYD CREAM RIPENER, '•THE STANDARD OF AMERICA," High-class Butter Makers and Experts everywhere indorse and use the Boyd Cream Ripener — "The Standard of America." It excels in every essential quality required for producing the best butter continu- ously, under varying conditions of temperature. Use the "Boyd" system as we direct, and you will be more than pleased with your results, and when you have your standard of excel- lence established you will know that you can maintain it easily and permanently. Sold under a positive guarantee. Send for our book on Cream Ripening. We solicit your orders for CREAMERY Supplies. We manufacture in our own shop a full and com- plete line of Drills: Oein.s suitable for every requirement of the dairy trade. Special machinery and our complete tinning plant enables us to turn out high-grade goods at low cost. STURGES, CORNISH & BURN CO. MANUFACTURERS OF HIGH GRADE Dairy Appliances and Supplies, Pasteurizing Apparatus for Iflilk and Cream, Etc. ST. PAUL. CHICAGO. KANSAS CITY. 134 We Are the Largest Manufacturers and Dealers in Apparatus and Supplies for Creameries, Cheese Factories, Dairies and M.HK. "Depots Iff THE, WO*RLV OUR LINE INCLUDES EVERYTHING PERTAINING TO MILK PASTEURIZATION. WRITE US FOR INFORMATION AND PRICES ON ANYTHING YOU MAY REQUIRE. CREAMERY PACKAGE MFG. CO., 1-3-5 WEST WASHINGTON STREET, CHICAGO, ILLINOIS. "SIMTLEJC" Patent Combined Churn and Butter Ulorker Patent "B. $ Ul." tDilk Check Pump Patent "B. & Ul/* milk Heater "facile" Babcock Testers Chr. Hansen's Danish Dairy Preparations Rennet Extract. Butter and Cheese color Prices quoted and Circulars furnished upon application for above, also on all Creamery, Cheese Factory and Dairy Apparatus and Supplies* D. H. BURRELL & CO. Little Falls, N. Y. 135 The Man Who "Reads -IS- The Man Who Also Things, and the man who thinks is the man we want to read our new Catalogue, as he will recognize the difference \/ between an article of merit .and one which is mad0 \r yT for the sole purpose of selling it cheap. You are the ~J£ man we want to reach, and we want to hear from you when you need anything in the line of Cream -Separators, ^Babcocf^ Testers, 'Butter 'Printers, 'Pasteurizers, MilK^ Heaters, Acid Miners, Combined Churn and 'Butter Workers, Cream Tan1(s, Cream Vats, Cheese Vats, MilK. Vats, Cheese Tresses. High grade Machinery and Apparatus of oil kinds for the Creamery, Dairy* or Cheese Factory. J0®=WRiTE FOR CATALOGUE M, THE SHA*RTLE*S; CoMTAjvy, 28. 3O and 32 3T. Canal *SV. CHICAGO, ILL. A. H. BARBER MFG. CO. 229 S* WATER ST., CHICAGO, ILL. BV/n^E-Rj* or Creamery Apparatus Dairy and MilK. Dealer's Supplies Pasteurizers, Milk Jars, Pulp Caps, Bottle Fillers, Bottle Washers, etc., etc* ALSO and lee Making machinery. FO*R CATALOGUE, 136 TABLE OF CONTENTS. Page Louis Pasteur 2-3 Introduction 5-7 CHAPTER I.— MILK AND ITS PRESERVATION. Chemical preservatives .8-9 Preserving by cooling 9 The Casse system of freezing .9-11 Preserving in vacuum : 11-12 Preserving with pressure 12-13 Preserving by electricity 13 Preserving by heat 13 Preserving by condensing 13-15 Condensing without vacuum 15-16 Preserving in powder form 16-17 Preserving by pasteurization 17-22 Intermittent pasteurization 22-23 Sterilizing 23-26 Preserving by carbonic acid gas 26 CHAPTER II.— THE PASTEURIZING HEATER. Continuous heaters 27-41 Regulators for heaters 41-43 Banishment government experiments with latest heaters. 43-47 Surface heaters 47-53 A new departure in heaters 53-56 Tank Heaters 56-61 Storage tanks 61-63 CHAPTER III.— THE PASTEURIZING COOLER, Coolers with exposed surface (13-65 Coolers with protected surface 65-67 Centrifugal coolers 67-68 Ice coolers . . • 68-70 137 CHAPTER IV.— PASTEURIZING IN THE CREAM- ERIES. Page Mikkelsen's foam killer 70-71 Shall wo make pasteurized butter? 71-78 CHAPTER V.— THE CITY MILK SUPPLY. Keeping accounts 78-80 The Stable 80-82 Milking and Milking Machines $2-83 Care of the milk 83 Straining milk 33-85 Filtering milk 85-87 Cleaning milk by centrifugal force 87-88 Preserving the milk for delivery 88 Farm coolers and aerators 88-90 Farm aeration 90-93 The milk pails and shipping cans 03-94 Pasteurizing on the farm 94-98 Co-operative milk shipping creameries 98-102 The bottles 102-103 Bottling and sealing 103-104 The city milk delivery 104-115 CHAPTER VI.— APPENDIX. Pasteurizing or sterilizing at home 115-116 Modified milk 116-117 Testing milk for buttrrfat 117-119 The Eaton portable tester 119-120 The acidity of milk 120-126 Testing heated milk 126-127 Sanitary dairying 127-130 A plea for belicr buildings 130-131 DAIRYMEN SHOULD READ Dairy and Creamery Papers and Books "Hoard's Dairyman" (weekly), Fort Atkinson, Wis ......................... SI. 00 '•Chicago Dairy Produce" (weekly), Chicago, -111 ............................... 1.50 "New York Produce Review" (weekly), New York ............................. 1.00 "Creamery Journal" (monthly), Waterloo, Iowa ................................. l 00 'American Cheesemaker" (monthly), Grand Rapids, Mich ..................... 50 "Elgin Dairy Report" (weekly), Elgin, 111 ........................................ 1.00 "The Dairy World" (monthly), Chicago, 111 ..................................... 1-00 "American Dairyman" (weekly), New York .................................. 1-50 "The Milk News" (monthly), Chicago, 111 ............................ ............. 1.00 "Pacific Coast Dairyman" (semi-monthly), Tacoma, Wash .................... 1-00 "The Western Creamery" (monthly), San Francisco, Cal ...................... 1 00 "The Milk Reporter" (monthly), Deckertown, N. Y ........................ 1-00 "The Dairy and Creamery" (semi-monthly), Chicago, 111 ...................... 1.00 "The Dairy Record" (weekly), St. Paul, Minn .................................... 50 "The Nebraska Dairyman" (monthly), Lincoln, Neb ......... . ................. 50 "The Dairy Age" (monthly), Topeka, Kan .................................. ...... 50 "A B C IN CHEESE MAKING," by J. H. Monrad. (Cheddar, Gouda, Skim Cheese, Brie, Neufchatcl, Cottage and Whey Cheese), Price 50c "A B C IN BUTTER MAKING," by J. H. Monrad. . . . Price 50c •'CHEESE MAKING IN SWITZERLAND," (Swiss, Brick and Limbur- ger), by J. H. Monnid ........ Price 50c "Feeds and Feeding," by Prof. W. A. Henry $2.00 "A Hand Book for Farmers and Dairymen," by Prof. Woll 1.50 "American Dairying," by H. B. Gurler 1.00 "Modern Dairying" (Grotenfelt), by Prof. F. W. Woll 2.00 "Dairy Bacteriology," by Prof. H. L. Russell 1.00 "Cheese and Butter Makers' Hand Book," by J. B. Harris 1.00 •'Cheese Making," by Prof. J. W. Decker 1.75 "A Treatise on Cheese Making," by G. E. Newell 50 "The Testing of Milk and Its Products," by Profs. E. H. Farrington and F. W. Woll 1.00 •'Indian Corn Culture," by Prof. C. S. Plumb.. 1.00 "Butter Fat and Dividend Calculator." by A. Schoenman 2.00 "Milk and its Products," by Prof. H. H. Wing 1.00 •'Common-Sense Ideas for Dairymen," by Geo. H. Blake 1.00 Mailed direct from publishers, on receipt of price, at buyer's risk, (unless 8 cents extra is remitted for registration). J. H. MONRAD, Winnetka, Cook Co., III. UNIVERSITY OF CALIFORNIA BRANCH OF THE COLLEGE OF AGRICULTURE THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW MAR 2 ality le itor n. r. 5m-8,'26 The *De LatJal Separator Co. Canal and "Randolph JV^., Chicago. GEJVE'RA.L OFFICES: 74- Cortlandt Street, - Jfeto Pasteruization* 3F259 *6 — 1901 59 : LIBRARY, BRANCH OF THE COLLEGE OF AGRICULTURE