the minimum on which a child of less than 1 year of age could 
maintain its weight. Any diminution of the quotient below this 
level was followed by a loss. Moreover, the researches of Czerny and 
Keller a liave shown that the energy quotient of 100 calories per 
kilo of body weight marks an upper limit which can only be tem- 
porarily surpassed without inducing disastrous nutritive and gastro- 
intestinal disturbances. These disturbances will be later discussed 
under the head of “ overfeeding.” 
A necessary part of these researches was the determination of the 
caloric value of mother’s milk. As human milk varies in composi- 
tion not only in different individuals but at different stages of its 
secretion from the breast, only average values could be found. Ac- 
cording to the richness of the milk, it varied from 014.2 to T23.9 when 
lactation was fairly established with an average caloric value of 650 
to the kilogram. 
The determination of the caloric value of any food substance is 
very easy once we know its percentage composition as one gram of fat 
produces 9.3 calories and one gram of proteid, and one gram of car- 
bohydrate have each a caloric value of 4.1. 
Thanks to these investigations we are now in a position to deter- 
mine most exactly, if desired, the amount of food required by each 
individual child in order to nourish it and give it growth and have 
furthermore, data by which we determine whether it is getting too 
much, in time to avert the disastrous consequences. 
METHODS OF FEEDING INFANTS. 
There are three methods by which infants may be fed (a) maternal 
nursing, (b) mixed feeding, part maternal and part artificial, and 
(c) artificial feeding exclusively. 
MATERNAL NURSING. 
Importance of maternal nursing . — The importance of maternal 
nursing can not be overestimated. Were mothers able universally to 
nurse their children, one-third to one-half of infant deaths would be 
expunged from our mortality returns. 
The number of women capable of nursing their children is prob- 
ably greater than is supposed. Von Bunge’s b statistics, gathered 
from all parts of Europe, tend to show that probably 75 per cent of 
all women could nurse their children. I have already adverted to the 
German city of Barmen where 63 per cent of all infants are fed at 
the breast. Professor Budin’s c statistics of the Clinique Tarnier in 
a Czerny and Keller, Des Kindes Ernahrung, Ernahrungssldrungen und 
Ernahrungstlierapie. 
6 Von Bunge, Die zunelimende Unfahigkeit der Frauen Hirer Kinder zu stillen. 
c Budin “ The Nursling.” 
