PO2 >. Studies in Metabolism. I 
the sugar content has reached the normal level. Then we tried 
to inject at 8 p.m. and to take our first sample early in the morn- 
ing. At first three rabbits were employed and after 0.1 to 0.15 
gm. per kilo of body weight was injected, no change of blood sugar 
was observed except in No. 19 which was doubtful. The dose 
was probably not large enough to produce hypoglycemia. We 
took four more rabbits and injected 0.2 to 0.25 gm. per kilo at 
10 p.m. We took our first samples the next morning but none of 
them showed hypoglycemia. Another 0.1 gm. per kilo was then 
injected into two rabbits and from 2 p.m. until the following day, 
over 24 hours, marked hypoglycemia was observed. Since the 
above dose is enough to induce hypoglycemia, the inference is 
drawn that the manipulation in taking the blood or the excita- 
tion of the animals accelerates the production of hypoglycemia. 
The Relation of Total Solids in the Blood to the Blood Sugar Content. 
The question arose whether this diminution in blood sugar was 
due merely to the dilution of the blood or to the effect on the 
sugar-regulating mechanism. To make this point clear the esti- 
mation of total solids of the blood was made. 
The following table shows that when samples were taken from 
normal rabbits during 12 hours the variation in sugar content 
was much, smaller than the variation in total solids. 
After a few days the same rabbits were used for injecting the 
TABLE VIII. 
Normal Variation of Total Solid and Sugar Percentage in Blood. 
9 a.m. 2 p.m. 7 p.m. 
Rabbit No. Date. a EE 
Sugar. Solid. Sugar. Solid. Sugar. Solid. 
1917 _| Percent per cent | per cent per cent per cent per cent 
25 Aug.’ 19} 0.116 16.4 0.111 16.4 0.114; 15.8 
26 + 20 0.115 17.4 0.105 16.0 0.108 15.1 
26 pe 22:|. 02125 15.3 0.126 14.8 0.122 13.8 
27 Hie da 0.114} 18.8 0.108 | 18.3 0-110 RP 21070 
28 Sept. 21 0.1238 16.1 0.1238 15.4 0.125 15.3 
29 es 21 0.104 16.6 0.111 15.8 0.103 14.9 
30 a ae 0.106 16.2 0.111 15.5 0.116 14.8 
dl = 23 0.111 15.2 0.114 14.8. 0.105 14.5 
Average 0.114} 16.5 0 
; ; 114] 15.9 0.1138 | 15.1 
