718 
lowing gastro-intestinal disturbances in infants a large number of 
apparent curds are mingled with the fecal discharge. They look 
like curds and have been taken for curds without further investiga- 
tion. Czerny has shown that they consist for the most part of saponi- 
fied fat, neutral fat, and fatty acids, interspersed in severe cases with 
clumps of bacteria. 
If infants are fed on fat-free cow’s milk, although the milk be 
undiluted and containing 3.50 per cent of bovine proteid, no trace 
of casein appears microscopically in the stools, yet Chapin tells us 
it is rare to find an infant 10 months of age who will digest more 
than 1.50 to 2 per cent of cow’s milk proteid. 
In this country, the digestibility of cow’s milk proteid has been 
confirmed by Walls 0 after a series of hundreds of observations. Now 
Czerny has shown that the persistent ingestion in a child of a diet 
with an energy quotient surpassing 100 calories per kilogram of body 
weight is invariably followed sooner or later by nutritional disturb- 
ances. Owing to the fact that infants receive for the most part 
nothing but milk, and that the percentage of sugar and proteid in 
milk is pretty nearly constant, it follows by reason of the high caloric 
value of the fat (9.3 calories) that a high energy, quotient implies 
an excess of fat. It is impossible, by mere inadvertence, with carbo- 
hydrate or proteid alone to get an energy quotient of a dangerous 
height without producing a food which either from its state of con- 
centration or by reason of its bulk would be obviously unfit to feed 
to any infant. On the other hand, slight increases of 1 or 2 per cent 
in the fat content of a food may have the effect of raising its caloric 
value to a dangerous extent. 
The action of an excess of fat in causing nutritional disturbances 
in infants operates in two ways; first, by reason of its action on the 
alkaline bases of the body, and second, by its influence on gastric 
digestion. 
Action of excess of fat on alkaline bases of body . — According to 
Czerny and Keller, the deleterious influence of an excess of fat in the 
diet is usually operative by reason of the abstraction such excess 
entails on the alkaline bases of the organism for the purposes of its 
saponification in the intestinal tract. It is evident that, owing to its 
high caloric efficiency and the greater difficulty of its oxidation as 
compared both with proteid and carbohydrate, the general capacity 
of the organism for the absorption of fat is strictly confined within 
narrow limits. Whereas an excess of proteids and carbohydrates is 
disposed of rather easily by the process of metabolism, with fats such 
is not the case. An excess of fatty food is not absorbed, but remains 
in the intestine and is there saponified. This is not due so much to 
® F. X. Walls, Am. Jour. Med. Sci., 1906, II. 
