642 JOHN R MUELIN 



2. Basal Metabolism. Three different observers have attempted to 

 secure the metabolism of the infant while fasting. Rubner and Heubner 

 compared the metabolism of a breast-fed infant 5^ months old and 

 weighing nearly ten kilos while on a full diet four days with his metabol- 

 ism on the fifth day when he received only tea instead of the breast 

 milk. The metabolism on the day of starvation was even higher than the 

 average of four days on food. 



Two objections may be urged against this experiment: First, that 

 no graphic record was obtained to prove that the infant was just as quiet on 

 the starvation as on the food days. It is almost unbelievable that such 

 should be the case. The second objection is that caffein is known to in- 

 crease metabolism and there is every reason to believe that the closely 

 related thein might have a similar effect especially upon an unhabituated 

 infant. Howland(&) tried an experiment in fasting in much the same way 

 with an infant three months of age, and weighing 4.65 kgm., giving tea 

 and saccharin instead of ^ milk and 5 per cent milk sugar which had 

 been the regular food. The result was the same : namely, that the metabo- 

 lism was not quite as low even when the child was known to be asleep as 

 while sleeping after a feeding. The first objection urged against Rubner 

 and Huebner's experiment would not, therefore, seem to apply, although a 

 graphic record giving proof that sleep while fasting was just as peaceful 

 as after feeding would be required to make the matter wholly convincing. 

 The second objection has not been removed. Schlossmann and Mur- 

 schauser(a) kept careful and continuous notation of the repose of their in- 

 fants, and determined the metabolism repeatedly on the three different 

 female infants from 87 to 180 days of age 18 hours after last food. All 

 received tea and saccharin which the authors used habitually to soothe 

 their subjects to sleep. The average minimal metabolism of the three 

 was 12.22 gm. CO 2 and 11.02 gin. O 2 per square meter (Meeh) of body 

 surface per hour, or 859 calories per square meter and 24 hours. 



It will be apparent from this recital that the whole question of basal 

 metabolism is complicated on the one hand by the difficulty of securing 

 perfect repose without any immediately preceding meal and on the other 

 hand by the question of age. None of the researches yet reported have 

 fulfilled in a wholly convincing manner the conditions now recognized as 

 necessary to secure the absolute basal metabolism of infants. We must 

 be content for the present, therefore, to speak of the lowest metabolism 

 obtainable under the various circumstances as the "minimal metabolism." 

 As landmarks of progress in this direction, the brief table on page 643 may 

 be borne in mind. 



It is somewhat hazardous to compare the results of different authors 

 obtained on different subjects by methods which are not strictly alike; but 

 the results suggest, if they do not prove, that the stage of digestion as well 

 as the age of the infant is a factor which must be reckoned with in at- 



