ANIMAL PRODUCTS 



275 



first detected by inspectors gave no ac- 

 curate information regarding the extent 

 of such frauds. 



On account of the existence of these 

 fraudulent practices, it has been found 

 necessary to adopt legal standards for 

 market milk. Some difficulty was met 

 in establishing standards on account of 

 the fact that the composition of milk 

 honestly and conscientiously collected 

 and cared for, may vary considerably 

 under different conditions. In actual 

 analyses of market milk the total solids 

 have been found to vary from 10 to 

 nearly 16 per cent, and the fat from 

 2.43 to 5.97 per cent. If, then, the high 

 standard be adopted, large amounts of 

 normal genuine milk would be con- 

 demned. If, on the other hand, the low 

 standard be adopted, it would be the 

 same as legalizing the additions of skim 

 milk, the removal of part of the fat and 

 utter indifference in the care of stock 

 and selection of breeds. Taking an av- 

 erage of numerous analyses as a good 

 basis on which to proceed we should 

 expect market milk to contain 12.52 per 

 cent of total solids, and 3.75 per cent 

 of fat. The legal standards adopted for 

 milk in different states vary in their 

 requirements from 11.5 to 13 per cent 

 for total solids, from 8 to 9.3 per cent 

 for non-fatty solids, and from 2.5 to 3.7 

 per cent for fat. The legal requirement 

 for fat in cream varies from 15 to 20 

 per cent and for butter from 80 to 83 

 per cent. 



All sorts of substances have been add- 

 ed to milk to conceal the fact that it has 

 been adulterated with water. The list 

 includes caustic soda, common salt, salt- 

 peter, sugar, starch, gelatine, etc. Chalk, 

 gypsum and calves' brains are sometimes 

 mentioned as adulterants of milk, but on 

 doubtful authority. As stated by Kobei 

 and others, turmeric, annatto, yellow coal 

 tar dyes and chromates have been added 

 to lend a yellow color to watered or poor 

 milk. 



Examination of milk — Inspectors first 

 determine the specific gravity and per- 

 centage of fat in milk. Suspicious sam- 

 ples may then be preserved for more 

 complete analysis if necessary. In states 

 in which the inspector depends princi- 

 pally upon the specific gravity of the milk 

 this is assumed to be 1.030 at 60° F. and 

 1.029 at 70° F. The specific gravity is 

 determined by the use of a lactometer, a 

 cylindrical glass instrument with a 

 graduated scale, which is placed in the 



sample of milk to be tested. If the 

 spindle of the lactometer floats below 29 

 the milk is probably watered, while if it 

 floats above 30 the milk has probably 

 been skimmed. There are several other 

 instruments for determining the fat in 

 milk, such as the lactoscope, creamom- 

 eter and lactobutyrometer, which need 

 not be described in this connection. The 

 farmer can readily determine the amount 

 of fat in his milk by the use of the 

 Babcock test, which will be described 

 under the subject of Dairying. If a 

 good quality of dairy cow be kept and 

 the proper care bestowed on them, the 

 farmer need have no fear about his milk 

 coming up to the standard so far as 

 fat content is concerned. 



Special analytical methods have also 

 been devised for the estimation of water 

 in milk by specific gravity and by deter- 

 mination of the total solids, for the de- 

 termination of nitrates and nitrites de- 

 rived from water, for the determination 

 of fat, or total solid and fat, by the Bab- 

 cock asbestos method, for the estimation 

 of albuminoids, milk sugar and free lac- 

 tic acid, as well as for the detection of 

 starch, annatto, coal tar dyes, chromates 

 and caramel. 



Preservatives in milk — As already 

 stated, milk, when freshly drawn, is of a 

 neutral or alkaline reaction. It soon be- 

 comes sour, however, under the influence 

 of bacteria and ferments. In order to 

 prevent this occurrence, various preserv- 

 atives have been used. The chemicals 

 which have been employed for this pur- 

 pose include formalin, boric acid, borax, 

 salicylates, benzoates, common salt, so- 

 dium carbonate, saltpeter, chromates, 

 etc. Lately most of these, except forma- 

 lin, have been discarded. 



Formalin — Worcester found that one 

 part of formalin to 100,000 of milk will 

 postpone curdling six hours, one part in 

 50,000 for 21 hours, one part in 20.000 

 for 48 hours, one part in 10,000 for 138 

 hours, one part in 5,000 for 156 hours. 

 Numerous experiments with formalin 

 leave no doubt that when used in the 

 proportion of one part in 40,000 to 

 50,000 it will prevent milk from souring 

 for 24 hours. This being established, an 

 equally important question immediately 

 arises regarding its wholesomeness. Wc 

 cannot enter here into the details of the 

 bitter controversy on this point, but will 

 mention only a few facts established by 

 experiment, 



