MILE, 487 
practically skimmed milk, which, if left to itself in not too cold a 
place, develops, through the action of a certain bacterium, lactic 
acid, with separation of the remaining casein. Such separated milk 
is now sold as a summer drink, being less sour than the old- 
fashioned skim milk. The popular notion that by taking away the 
cream beforehand all the goodness is lost, is quite a misappre- 
hension for considerable curd is still held in solution, as well as 
milk-sugar ; and if bread and butter, or a piece of chocolate, be 
taken with the separated milk, then the full value of the original 
new milk is obtained, this drink being meanwhile cheaper than 
beer, and preferable thereto. For sterilizing milk, a temperature of 
190° Fahrenheit is under ordinary conditions a safe and easily 
practicable course ; and to heat the milk once thus is all that 
is necessary. Being treated in this way, the milk will remain 
sterilized in a room at an ordinary temperature for twenty, or 
thirty hours, even in warm weather. But Professor Koch 
pronounces that to boil milk does not exterminate the bacilli 
of tuberculosis, whilst sterilizing milk impairs its nutritive 
quality. The more any natural food is altered from its natural 
state, the more likely is it to produce scurvy; for example, as 
by sterilizing new fresh milk. This, when unboiled, contains in 
one quart as much citric acid (such as that of lemons, oranges, 
and potatoes) as occurs in a large lemon. But when milk is 
subjected to boiling, its power of continuing to hold this acid 
(as citrate of lime) unchanged, is much diminished, the same 
becoming converted by heat into the comparatively insoluble 
crystallizable form: the chemical reaction produced being that 
of converting the bicitrate of calcium into a less soluble 
tricitrate of calcium. Infantile scurvy is most prevalent among 
the classes where a child’s diet is carefully restricted to boiled 
milk. 
When a patient’s digestion is very weak, if living in the country, 
or keeping a cow, he should make a dietetic trial of “ strippings,” 
that is, the milk obtained by re-milking the cow soon after it 
has been already milked. The supplementary milk will flow 
in quite a thin stream, at the end of the first milking, being rich 
in cream as fattening food, but containing very little casein, or 
more heavy proteids, and being thus less difficult of digestion 
than the first milk. In acute disease of the kidneys, a milk 
diet is found to increase the output of urea (poisonous, if retained) 
and of other solids, whilst diminishing the amount of morbid 
