210 DOMESTIC ANIMALS, DAIRYING, ETC. 



tion between the thunderstorm and the souring of milk is one of a 

 different character. Bacteria certainly grow most rapidly in the 

 warm, sultry conditions which usually precede a thunderstorm, and 

 it frequently happens that the thunderstorm and the souring occur 

 together, not because the thunder has hastened the souring, but 

 rather because the climatic conditions which have brought the storm 

 have at the same time been such as to cause unusually rapid growth 

 of the bacteria. This fact has been verified by many experiments 

 which have shown that without the presence of lactic organisms there 

 can be no spontaneous souring of milk. Milk deprived of bacteria 

 will certainly keep well during thunderstorms. Dairymen find no 

 difficulty in keeping milk if it is cooled immediately after being 

 drawn from the cow and is kept cool. Milk submerged in cool water 

 is not affected by thunderstorms. Dairymen find that during "dog- 

 day" weather, even when there is no thunder, it is just as difficult 

 to keep milk as it is during thunderstorms, and they also find that 

 scrupulous cleanliness in regard to the milk vessels is the best pos- 

 sible remedy against souring during a thunderstorm. It is safe to 

 conclude, therefore, that in all cases it is the bacteria which sour the 

 milk, and if there seems to be a casual connection between the 

 thunder and the souring it is an indirect one only; climatic condi- 

 tions have hastened bacteria growth and have also brought on the 

 thunderstorm. The same conditions would affect the milk in exactly 

 the same way even though no thunderstorms were produced, and this 

 effect, our dairymen tell us, is frequently observed during the warm, 

 sultry autumn days. 



FERMENTED MILKS. 



Food Value of Fermented Milk. The high food value of milk 

 is too generally recognized to need discussion here ; fermented milks 

 also have a high food value, except that in some cases the fat is 

 partially or entirely removed. Otherwise the food value of the fer- 

 mented milk differs little from that of the fresh milk from which' 

 it is made. Any increased digestibility of the fermented milk is due 

 not so much to change in the chemical nature as to the fact that 

 the casein is furnished in a precipitated and finely divided condi- 

 tion. In none of the fermented milks is there any material cleavage 

 of the casein resembling the digestion in the stomach. The fat is 

 almost unchanged, and a part only of the sugar is converted into 

 acid, alcohol, or gas. In certain gastric troubles in which it is diffi- 

 cult to find any food that can be retained by the patient, fermented 

 milks are frequently used with good results. Kefir and kumiss 

 especially are used under such circumstances, as the stimulating 

 action of the carbon dioxid which they contain is believed to aid in 

 their digestion. The value to the physician of a highly nutritious 

 food which can be digested when other foods are rejected is obvious. 



Therapeutic Value of Fermented Milk. Fermented milks have 

 been used since very early times, and it is probable that their value 

 in treating intestinal disorders has been known in an indefinite 

 way for centuries, but it is only in recent years that their therapeutic 

 possibilities have been recognized by physicians. The development 



