712 
DE. E. SMITH ON THE CHEinCAE 
5. The factor of the respirations to equal the number of the pulsations varied in the 
different persons, increasing with their age, from 4-63 to 5-72, and on the average was 
5-15. 
6. Half of the product of the respirations and pulsations very nearly equalled the 
number of cubic inches of air breathed in several of the cases. No such numerical rela- 
tion could be found in reference to the carbonic acid. 
7. The variations of the carbonic acid in the same day, with food, were so great as 
an average of 10-43 grs. and 6-74 grs., and extremes of 6-96 grs. and 13-3 grs. ; but m a 
prolonged fast the extreme difference was less than 1 grain. 
8. In a prolonged fast of twenty-seven hours, the diminution per cent, from the quan- 
tities on a day with food, was 26 of carbonic acid, 30 of air, 37 of vapour, -7 of rate of 
respiration, and 6 of rate of pulsation. The loss of carbon in the twenty-four hours is 
equal to that contained in 20 oz. of bread. The returns were so uniform, that the 
quantity of carbonic acid expired at the end of twenty-seven hours was the same as at 
4^ hours after food. 
9. There is a normal or basal line below which the system does not pass in health 
and wakefulness, and which is tolerably uniform. It is the same in the complete absti- 
nence from food, as at the end of the interval between meals. There is also, when at 
rest, a higher point, which the system does not exceed, due to food, and it is the highest 
after breakfast and tea. 
10. There is an increase of carbonic acid in the absence of food, at or near to the 
period when it usually increased with food. 
11. There are variations from day to day, in the absence of food and exertion, which 
are dependent upon the amount of waste and supply of the preceding day and night. 
Cceteris paribus, the more food, rest, and sleep, the greater will be the quantity of car- 
bonic acid evolved on the following morning. 
12. There are great variations from season to season, so that, as the hot season 
advances, all the respiratory phenomena are lessened. The diminution in myself at the 
middle of August was 30 per cent, of air, 32 per cent, in rate of respiration, and 17 per 
cent, of carbonic acid. In Mr. Moul, to the middle of June the diminution was 27 per 
cent, of air and also of carbonic acid, and 28 per cent, in the rate of resphation. 
Spring is the season of the greatest, and the fall, of the least acthity of the resphatory 
and other functions. 
13. Temperature and atmospheric pressure only partially explain the effect of season ; 
for with the same temperature, at different seasons, there is great diversity in the car- 
bonic acid expired, and particularly with a medium temperature ; as, for example, 59 . 
with which the quantity of carbonic acid was 9-13 grs. in the spring, and 6-/ 6 gis. in 
the summer and autumn. The relation of temperature and pressure to the carbonic 
acid is an inverse one, the former acting in an increasing ratio in cases of sudden 
increase, and with so much power that 2-3 grs. of carbonic acid per minute were lost m 
seven days. 
