DAIRY FARMING DAIRYING. 495 



The composition and analysis of milk, II. I ». Richmond i Ana 

 No. 355, pp. 325 ■ The average composition of 15,910 Bamples of milk analyzed 

 during L904 was as follows: 



Specific gravity, 1.0322; total Bolids, 12.68 per cent; fat, 3.74 percent; and sol 

 not-fat, 8.94 per cent. The average fat contenl of the morning milk was 3.52 per 



centand of the evening milk 3.96 percent. The average fat < tent was 0.09 per 



cenl lowerthan in L903, as a cause of which it is suggested that on account of weathei 

 and soil conditions the fodder crops grown in L904 were no1 of the same qualil 

 in t he years immediatelj preceding. 



It was found thai in burning a sample of milk 0.008 per cent of the chlorin was 

 lost. Analyses are reported of human milk, and of buttermilk prepared by churn- 

 ing Bweet cream, sour cream, and sour skim milk. A preparation advertised as a 

 milk preservative and claimed to consist of nothing bu1 constituents of milk was 

 found to contain hydrogen peroxid, sodium chlorid, sodium phosphate, potassium 

 carbonate, and another potassium salt not identified. 



Owing to a want of agreement of authorities as to the correcl volume ol one divi- 

 sion of the neck of the Gerber bottle, this and related questions were investigated. 

 The conclusion was readied that 0.126 cc. was the besl value for one scale division. 

 The volume of fat obtained by the Gerber method was found to exceed that of the 

 actual fat present, the mean ratio being L.025. This increase is believed to be due 

 to a change in the composition of the fat. The author estimates the volume of fat 

 between the upper and lower layers of the meniscus as equal to 0.08 per cent, and 

 believes that this amount, which is always neglected in reading, i^ partly compensated 

 by the decrease of the weight of milk with increasing quantities of fat as delivered 

 by an 11 cc pipette. The exact diameter of the neck of the bottle is not believed to 

 be of importance. 



The analysis of samples of milk referred to the government laboratory in 



connection with the sale of food and drugs act, T. E. T ;ri: (Analyst, SO 



(190.~>), No. •-'•'/, pp. 197-205). — The samples of milk in question are invariably sour 

 and hence a study has been made to determine if this fad prevents a true infer- 

 ence being made as to the character of the fresh milk. 



Of 13 samples of genuine milk kept for periods varying from 2 to \\\ weeks the 

 decrease in fat content averaged only 0.06 per cent. These results were not affected 

 by the addition of water. Souring, therefore, does not affect to any important extent 

 the fat in milk. 



The loss in solids-not-fat during the same time was <>.L ; 4 t<» 0.87 per cent for 

 genuine milks and 0.23 to 0.68 for watered milks, due mainly to the production of 

 alcohol and volatile acids. The total loss in solids varied as a rule from 0.2 to 0.5 

 per cent, and it is considered that a determination of solids within these limits is 

 satisfactory from the standpoint of inspection. 



Twenty gallons of milk was diluted with one-fourth its volume of water and kept 

 in stoppered bottles at about L8 < '. for 10 to 12 weeks, [n this were found 76.4 gm. 

 ethyl alcohol, about 390 gm. of normal butyric acid, 116 gm. acetic acid, nearly 2 



gm. «>f an acid of higher lecular weight than butyric acid, ammonia, and traces of 



propionic acid. "Hence, therefore, it may be considered proved that by far the 

 greatest portion of the volatile products of the fermentation of milk, other than water 

 and carbon dioxid, are ethyl alcohol, acetic and butyric acids, ami a small quantity 

 of ammonia." 



The methods of analysis employed in the Laboratory are described. 



The morphology of milk and colostrum secretion, J. Arnold i Beitr. Path. 

 A, nit. u. AUg. Path., 38 (1905), No. 9, pp. &1-44S, pi t).— According to the histo- 

 logical studies of the author, the Becretion of milk fat depends upon a transforma- 

 tion of the cytoplasm of the mammary epithelial cells w hich are not destroyed in the 

 process. The first drops of fat appear in the basal portion of the cell and in t he 



