276 



FARMER'S CYCLOPEDIA OF LIVE STOCK 



Price has shown that formaldehyde in 

 the proportion of one to 2,500 does not 

 interfere with the action of the rennet 

 in coagulating milk, while in the propor- 

 tion of one to 1,875 it retards coagula- 

 tion and at a rate of one to 500 makes 

 it impossible for rennet to coagulate 

 milk in 18 hours. Formaldehyde used 

 at the rate of one to 125 did not interfere 

 with digestion by pepsin. Similar re- 

 sults were obtained with formaldehyde 

 and other digestive ferments in experi- 

 ments carried on in glass vessels. For- 

 maldehyde used at the rate of one to 

 20,000 preserved the milk for 48 hours 

 and prevented the development of com- 

 mon bacteria in the milk. The bacteria 

 were killed when the formaldehyde was 

 used at the rate of one to 1,560. 



Eecently Von. Behring has recom- 

 mended the use of formalin in the pro- 

 portion of one to 40,000, particularly in 

 the milk of tuberculous cows. It is 

 urged that the formalin in that strength 

 will not harm children or calves, that it 

 will kill the tubercle bacilli but will not 

 destroy their vaccine, and that the use of 

 milk thus treated not only does not pro- 

 duce immediate infection with tubercu- 

 losis but serves as a natural process of 

 vaccination against th,e disease. Many 

 sanitarians, however, have declared pos- 

 itively against the use of formalin un- 

 der any circumstances. In fact, there 

 seems to be no legitimate excuse for the 

 use of any chemical preservative in milk, 

 for milk may be kept sweet and delivered 

 sweet to patrons in cities 300 or 400 

 miles from the producer by the mere ob- 

 servance of cleanly habits and the use of 

 ice. Milk is produced twice per day and 

 should be used within 24 hours. It does 

 not sour within this period unless filth 

 and bacteria have been allowed to get in- 

 to it. The use of preservatives suggests 

 filth and serves as an excuse for filthy 

 habits and unclean surroundings in the 

 dairy. 



Borax does not preserve milk unless 

 used at a rate of 10 grains per quart. 

 With regard to the influence of borax on 

 man, the most authoritative results have 

 been announced by Wiley on the basis 

 of actual, long-continued experiments 

 on healthy men. Wiley found that 

 "when pushed to the limit of toleration 

 the quantities of the borax or boracic 

 acid which produce nausea, vomiting 

 and loss of appetite vary greatly with the 

 individual. In some cases these symp- 

 toms were produced by from 3 to 4 grams 



daily, while in other instances these 

 quantities could be tolerated. For this 

 reason the protection of those more sen- 

 sitive to the influences of these preserva- 

 tives seems to be a wise and just 

 measure." 



Sodium carbonate is not used as a 

 preservative but to neutralize the acid- 

 ity of milk, which has already soured. 

 Its use is therefore a deliberate fraud. 

 Salicylates, benzoates, chromates and 

 saltpeter are rarely used in the United 

 States for the preservation of milk. 

 Technical methods have been devised 

 for the detection of all these preserva- 

 tives, but a description of them would 

 not be in place here. 



Bacteria in milk — As already stated, 

 milk when secreted in the healthy ud- 

 der is practically free from bacteria — 

 not absolutely free, for bacteria may 

 penetrate through the teats into the ud- 

 der to a greater or less depth. The ac- 

 tual number in milk as drawn from the 

 udder may be 200 to 300 per cubic centi- 

 meter. These bacteria, however, are of 

 a harmless nature and have little or no 

 effect in souring the milk or otherwise 

 changing it 



In all inflammatory conditions of the 

 udder known as mammitis or garget, as 

 well as in cases of tuberculosis, anthrax, 

 rabies, tetanus, pleuro-pneumonia, foot 

 and mouth disease, etc, the milk may 

 contain bacteria of a harmful nature or 

 virus derived from the cow. When the 

 cow is healthy the bacteria in milk 

 come from the milk duets, the outside 

 of the cow, the air. milk utensils and 

 milker. 



Bacteria in teats — The milk duct in 

 the teat and the milk cistern at the up- 

 per end of the teat nearly always con- 

 tain bacteria in considerable numbers. 

 They make their entrance through the 

 teat from the outside. The first few 

 streams of milk, or the foremilk, there- 

 fore, may have a high bacterial con 

 tent. The foremilk should not be saved, 

 for it contains a very low percentage of 

 fat in addition to being contaminated 

 with bacteria. 

 . Common sources of contamination — 

 As soon as the milk is drawn it is sub- 

 ject to bacterial contamination. The 

 cow, herself, is probably the most im- 

 portant source of bacteria. The skin 

 and hair of the cow, even in the best 

 groomed dairies, carry some filth and 

 bacteria. These may be rubbed off by 



