663 
The firm, pale-gray stools so characteristic of this condition are 
composed largely of fatty soaps (Seifenstuhlen) . Czerny and 
Keller ascribe the pathology of this condition to the action of fat 
in extracting the alkaline bases already alluded to, as shown by the 
increased elimination of ammonia in the urine. They regard this 
elimination of ammonia salts due to the fact that the alkaline bases 
are so largely drawn upon from the body to saponify the excessive 
amount of fat accumulated above the needs of the organism in the 
intestine, that in order to satisfy the normal acid products of metab- 
olism the ammonia salts are drawn upon. 
Percentage system of artificial feeding . — In this manner we see di- 
vergent points in this view of the whole question of infant feeding 
as compared to that in vogue on this side of the Atlantic. The per- 
centage system of modification of milk rests upon the following 
premises, two of which are certainly faulty: 
First. Thai a substitute for mother’s milk must resemble it in the 
relation and chemical composition of its ingredients ; 
Second. That this condition is fulfilled only by some milk; 
Third. That cow’s milk is the only practical substitute ; 
Fourth. That the chief difficulty in the use of cow’s milk is the in- 
digestibility of its proteid by infants ; and, consequently, 
Fifth. The composition of cow’s milk must be so altered by appro- 
priate manipulation as to provide those relative proportions of pro- 
teid, fat, and milk-sugar which experience teaches us is suitable for 
the different ages of the child. 
We will now proceed to discuss wherein these principles are erro- 
neous. The error seems to be embodied in principle 4 and princi- 
ple 5. 
The fourth principle, i. e., that the casein of cow’s milk is indiges- 
tible, has been shown to rest upon a misconception. It only helps 
in a mechanical manner to produce indigestion when combined with 
large quantities of fat. or is altered in its digestive quality by fermen- 
tative changes in the milk at the time of consumption. 
It is the taking of this assumption for granted that has caused 
the rather numerous instances of overfeeding in the case of American 
children. In fact, under our present system overfeeding is apt to be 
the rule rather than the exception. By reason of the belief that the 
proteid of cow’s milk is the essential indigestible portion of its in- 
gredients, it has been reduced, in the milk modifications prescribed by 
many of our physicians, almost to the point of extinction in certain 
individual cases. 
Realizing, however, that food offered to a child must contain cer- 
tain elements of energy, the place of the proteid has been supplied 
by the use of fat, which, until in recent years, has been regarded 
digestible by many of our pediatrists and to act in conjunction with 
