December 6, 1889.] 



SCIENCE. 



terials : ration No. i, 15 kilograms of meadow-hay and 2 kilograms 

 of linseed cake ; No. 2, siloed grass ad libitiim, and 2 kilograms of 

 linseed cake; No. 3, 20 kilograms of beets, 8 kilograms of hay, and 

 2 kilograms of linseed cake ; No. 4, pasture-grass ad libit iim ; No. 

 5, chopped clover with 14 per cent of other grasses ad libitum. 



The highest melting-point observed, viz., 40.5, was from ration 

 No. I ; and the lowest, viz., 32.5, from ration No. 5. The highest 

 volatile acids were produced by No. 3 ; the lowest volatile acids 

 were observed with ration No. 2. 



The results of my analyses were obtained on the first samples of 

 butter sent by Mr. Harrington, and were published w\ Agricultural 

 Science for April i, 1 889, pp. 80 rf .5<»y. Not fully satisfied with 

 the result of a single determination, I asked Professor Harrington 

 to send me other samples of butter, which he did on two subse- 

 quent occasions. The analyses of the two last sets of samples 

 sent did not fully bear out the results obtajned in the first set. 



The importance of a more careful study of this subject led me to 

 institute some feeding experiments of my own, in order to unravel, 

 if possible, the mysteries of the preceding analyses. I accordingly 

 obtained authority from the secretary of agriculture to arrange for 

 certain feeding experiments with Professor Alvord of the Maryland 

 Agricultural Experiment Station. Three cows were selected for 

 these experiments, described by Professor Alvord as follows : No. 

 I, full- bred Jersey ; No. 2, full-bred Ayrshire; No. 3, cross-bred 

 Jersey and Ayrshire. 



These cows were kept on ordinary pasturage for ten days, and 

 then the milk from each of the cows for three days was taken for 

 the experiments. All the milk was subjected to the same condi- 

 tions. It was set in earthen bowls in a refrigerator at 45° to 

 50'^ F., and skimmed after twelve hours. The cream was mixed 

 and kept at 55° to 60" until the fourth day after the beginning of 

 the milkings. The cream was then ripened in a room at 60° F. 

 temperature for twenty- four hours. After cooling to 62"^ F., the 

 cream was churned ; the temperature rising from 62° F. at the be- 

 ginning of the churning, to 65° at its close. The time required for 

 each churning was twenty minutes. The three days on which the 

 milk was saved were damp, hot days, very unfavorable for making 

 good butter. In all cases the butter was thoroughly washed in 

 cool well-water, made into rolls, and put in glass jars. One-half 

 of each sample of the first lot was salted at the rate of two-thirds 

 of an ounce of salt to one pound of butter. 



After the conclusion of the first set of experiments, the cows 

 were gradually changed to a ration of cottonseed- meal, using the 

 commercial variety, such as is used for fertilizing purposes, as no 

 unextracted cottonseed-meal could be obtained at this season of 

 the year. The ration of cottonseed-meal was gradually increased, 

 the cows finally being given all they would eat of it. The follow- 

 ing are the facts as to the second lots. The feeding of cottonseed- 

 meal was commenced on the 25th of July, giving but one pound at 

 a feed at first, but constantly increasing the quantity. 



During this trial the cows were turned into a small lot with very 

 short pasturage, for exercise and access to running water. They 

 were fed only the cottonseed-meal, and consumed the quantity 

 stated. At the close of the trial, the Jersey and cross-bred cows 

 were beginning to refuse the meal. The Ayrshire continued to eat 

 all offered, and probably could have been fed twelve pounds a day ; 

 but I was afraid to give her over eleven pounds a day, and did that 

 only twice. She later kept on at eight and ten pounds per day, 

 while the others fell to one pound and two pounds. 



In general, the data obtained corroborate the results of the first 

 study of the samples sent by Professor Harrington. The melting- 

 points of the butters from cows fed on cottonseed meal are 

 markedly higher than from the other samples. There is also a mark- 

 edly diminished content of volatile acids in these butters, and a 

 lower iodine absorption power. The latter character is unlike the 

 Harrington samole. Another characteristic phenomenon noticed 

 in the first samples of butter is also here repeated ; viz., the persist- 

 ence of the reducing agent which is present in cottonseed-oil in the 

 butter derived from animals fed thereon. The physiological im- 

 portance of this phenomenon will be mentioned in another place. 

 The most curious results, however, of these experiments is found 

 in the increase in the butter of the glycerides having a high melt- 

 ing-point ; in other words, the glycerides of the palmitic and stearic 



series. While further experiment may be necessary to show that 

 there is a uniform diminution of volatile acids in butters from cows 

 fed on cottonseed-meal, the fact is now most clearly established 

 that the melting-point of such butters is uniformly higher. In re- 

 gard to the absorption of iodine by the butters from cottonseed-fed 

 cows, the results obtained are somewhat at variance with those 

 secured by Ladd, who states that butter from cows fed on linseed- 

 meal contained 3.5 per cent more oleine than those samples which 

 were obtained from cows fed on bran. This conclusion of Ladd's. 

 however, may not be the true one, since linseed-oil has an iodine 

 absorption of about 155 per cent, and this high coefficient may 

 have had some influence upon the butter as regards iodine absorp- 

 tion. It is possible, therefore, that some of the linoleic glyceride, 

 which has so high an iodine- absorbing power, may have found its 

 way into the butter, thus increasing its iodine absorption. 



Another important characteristic of the butters examined is seen 

 in their abnormally low content of volatile acids. If we compare 

 the samples from the Maryland station with those from Kansas,, 

 we have a very characteristic contrast between abnormal pure but- 

 ter and normal pure butter. The two samples from Kansas show 

 a percentage of volatile acids which is not unusually met with in 

 samples of pure butter. On the other hand, the samples from the 

 Maryland station show an abnormally low content of volatile acids. 

 This percentage of volatile acids is indeed so low that these butters 

 would be condemned as spurious if we relied upon the volatile acid 

 test alone. It does not seem so strange, in the light of these facts, 

 that Allen should have found abnormal Danish butters which, 

 nevertheless, from their history, were certainly genuine. 



In so far as the breed of the animal is concerned in the above 

 experiments, it does not seem to have greatly influenced the com- 

 position of the butter. The low content of volatile acids may 

 therefore be attributed either to the pasturage, or to the peculiarity of 

 the animals themselves, or to the period of lactation. It would 

 hardly seem probable, however, that three animals taken at random 

 should have exhibited in almost the same degree the abnormal 

 qualities indicated in the composition of the butters. 



The physiological questions which are suggested by the above 

 study are of the utmost consequence. In a paper entitled " Note- 

 on the Action of Digestive Fluids on Oil," published in The Medi- 

 cal News of July 28, 1888, I called attention to the remarkable in- 

 fluence exerted on a large quantity of oil in the human digestive 

 organs. A pint of oil, presumably sweet-oil, but more likely cot- 

 ton-oil, was administered to the patient for the relief of an obstruc- 

 tion in the gall-duct. This oil, in passing through the digestive 

 organs, was completely decomposed mostly into fatty acid with 

 some soap, forming an emulsion in the alimentary canal, and, being 

 voided in the form of rounded masses of considerable consistence, 

 was mistaken by the patient for gall-stones. This action of the 

 digestive liquids was entirely unexpected, and seems to show that 

 the commonly accepted notion that the fats are acted upon in the 

 digestive organs by being emulsified, and thus absorbed into the 

 circulatory fluids, is an erroneous one. 



It is the common supposition that the facts have for a physiologi- 

 cal function the maintenance of the animal heat of the body, and 

 the nutrition and supply of the fatty portions thereof. 



The experiments in feeding cows on cottonseed-meal would 

 seem to indicate that the natural glycerides contained in cotton- 

 seed-meal do not appear in the butter of the cows fed thereon. If 

 the cottonseed-oil in the food should pass unchanged into the butter,. 

 we might, it is true, have a lowering of the volatile acids ; but this 

 would be accompanied by a great increase in the iodine absorption 

 and a marked lowering in the melting-point. It is quite certain 

 that the glycerides of butter which yield on saponification volatile 

 acids are not derived from similar glycerides in the food of the 

 animal. It may also be quite true that none of the glycerides in 

 the butter of the cow is derived from the fat of the food of the 

 animal. It is more than likely that the fat of milk is a direct prod- 

 uct of digestion, and is formed conjointly from the carbohydrates 

 and the albuminoids in the cow's food. We need not, therefore, 

 be perplexed any longer at the presence of so small a portion of 

 stearine and so large a proportion of the butyric series of the 

 glycerides in the fat of milk. 



From the evidence already at hand, I think we would be justified 



