MILK. 481 
or in travelling, should always be diluted with at least ten times 
its bulk of water. In rickets, any excess of milk is to be avoided 
in the child’s food, or aught else of the animal sort which causes 
stinking stools. The added cane-sugar prevents condensed milk 
from approaching the standard of human milk. 
When milk enters the stomach, it sets into a solid clot, owing 
to the action on it, not at first of gastric juice, but of rennin; 
whilst the alkaline salts of the milk serve for a short time to 
partly neutralize the strong acid of the gastric juice, thus giving 
the rennin time to act, just as in making a junket with calf’s 
rennet by the cook. Boiled milk clots more slowly outside the 
body than raw milk does, and with a less dense clot ; but this 
is not the case within the stomach, as is often supposed by 
mistake, because the gastric juice redissolves the lime salts of 
the boiled milk, which then clots quite as firmly as does unboiled 
milk within the stomach. The change which takes place when 
milk turns sour by keeping, or in thundery weather, is caused 
by the growth in it of micro-organisms, which can be killed by 
heat (short of boiling). These micro-organisms are most active 
in milk at blood-heat, but scarcely at all in milk at 60° Fahr., 
and quite inactive at the freezing point. Alter being boiled, milk 
is free for a time from micro-organisms, but it will not remain 
so unless straightway sealed hermetically from the air, so as 
to prevent the entrance of fresh germs» which would shortly 
become very active therein. 
When milk is allowed to remain exposed to the air in a cool 
place, the ‘“‘ bonny clobber,” or sour milk, is produced in this 
wise. Some clot or cream collects on the top, and a mycelium, 
or membrane of delicate fungi, also forms on the uppermost 
surface of the milk, which now acquires an acidulous taste, 
and is sometimes a little effervescent, whilst curdling in the same 
way as it would by rennet; though this present curdling is 
caused by lactic acid, developed from the sugar of milk by 
a living low fungus and ferment termed the “bacillus of 
sour milk.” Although generally rejected, yet sour milk is an 
agreeable, nutritious fluid, easily digested. It should be well 
stirred before use, and perhaps have some cream added; the 
taste can be heightened by white sugar and powdered cinnamon, 
with dice of bread, or bread crumb, to give it body. Lactic 
acid, when neutralized with an alkali, such as carbonate of soda, 
makes a useful hypnotic for sleepless patients with nervous 
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