370 EXPERIMENT STATION RECORD. 



in the solids is fairly constant at about 25 per cent. As the ash is nearly con- 

 stant the percentage of ash in solids increases as the solids diminish, being 4.9 

 per cent in Jer.sey milk and 6.7 per cent in Holstein milli. Sugar is also nearly 

 constant and the percentage in the solids increases as the solids decrease, being 

 30 per cent in Jersey milk and 40 per cent in Holstein milk. Hence, both the 

 ash and lactose content are of value in detecting added water. 



It is stated that "it is possible, within reasonable limits, to indicate from the 

 percentage of solids and fat whether or not a sample has been watered, 

 skimmed, or is normal milk. No relation exists between the i-efraction of the 

 serum and the sour serum a.sh; therefore, if both figures are below the mini- 

 mum for pure milk it is positive indication of the presence of added water. 

 The protein-fat ratios in all cases have been less than 1. If this figure exceeds 

 1, skimming is indicated, the amount being greatest in samples possessing the 

 highest ratio. If the protein-fat ratio is less than 0.7, or the percentage of fat 

 in the solids is above 35, samples may be declared watered by a low refraction 

 of the serum, not necessarily below the minimum for all samples of known 

 purity. This is particularly so when dealing with herd milk. In the absence 

 of a refractometer, the specific gravity or the percentage of solids of the serum 

 is just as valuable as the refractive index in detecting added water." 



The iron content of milk, F. E. Nottbohm and G. Dore {Ztschr. Untersuch. 

 Nahr. u. Gemissmtl., 28 {WW, No. 9, pp. 417-424) .—From their studies the 

 authors find that the normal iron content of milk, on the basis of FesOs, is 

 between 0.03 and 0.13 mg. in 100 cc, the majority of samples ranging between 

 0.03 and 0.07 mg. Toward the end of the lactation period the iron content 

 increases. An Increase in the iron content due to inflammatory conditions of 

 the udder (mastitis) can not always be counted on. The feeding of sac- 

 charated iron to cows apparently does not increase the normal amount of iron 

 in the milk. 



Dairies and cow sheds. — Their effect upon the purity of the milk supplied 

 to military hospitals, troops, and married families, E. B. Dewberry {Jour. 

 Roy. Army Med. Corps, 21 {1913), Nos. 5, pp. 570-580, figs. 4; 6, pp. 676-683).— 

 General instructions are given on the construction and care of cow sheds and 

 the sanitary care of milk. 



Shrinkage in handling milk at city milk plants {Cream, and Milk Plant 

 Mo., 3 {1914), No. 3, p. 22). — Estimates were obtained from 41 dealers by the 

 Dairy Division of the U. S. Department of Agriculture as to the daily losses in 

 the handling and delivery of milk. These estimates, which include all losses 

 in handling milk from the time it is shipped, varied from 0.5 to 4 per cent and 

 averaged 2.15 per cent of the amount handled by each dealer. Investigation 

 revealed many unnecessary leaks Avhich appear to be negligible but amount 

 to a considerable sum in the course of a year. Among the ways in which 

 these losses occur are the following: "Leaky cans; dented or battered cans; 

 cans not full ; careless handling of cans, both in transferring from cars and in 

 dumping; inefficient draining of cans; leaky or battered apparatus; filters out 

 of repair, as leaky valves; losses at the filler (this may be caused by the 

 valves not being properly adjusted, carelessness in handling, breakage of bot- 

 tles, etc.) ; carelessness in handling full cases of milk, thus breaking the bottles; 

 loss from not removing all the milk from the pasteurizer, pipes, pumps, tanks, 

 or other apparatus; loss from the process of pasteurizing and clarifying, by 

 evaporation and mechanical losses." 



Experiments with commercial and homemade starters, L. Funder {Aarsber. 

 Offentl. Foranst. Landbr. Fremmc, 1913, III, Statsforattst., pp. 6S7-720, figs. 3; 

 abs. in N. Y. Produce Rev. and Amer. Cream., 38 {1914), No. 14, p. 592).— The 

 results of these experiments are summarized as follows : 



