BLOOD. 



129 



It is thus seeu that^ in general, the amount of carbonic acid 

 expired by both sexes increases with age up to a certain point — 

 the 40-45th year, and then diminishes ; that the quantity of 

 carbonic acid expired increases with the development of the 

 muscular system ; that women expire less carbonic acid than 

 men; that the formation of carbonic acid attains its max- 

 imum at the commencement of menstruation, and then expe- 

 riences no further increase, except in the pregnant state, until 

 the cessation of menstruation, when an increase again takes 

 place. On an average, an adult male, of moderate constitution, 

 exhales from 160 to 170 grains of carbon per hour; an adult 

 female in the unimpregnated state, from 100 to 110 grains; 

 during pregnancy, 125 grains ; and after the cessation of the 

 catamenia, from 116 to 130 grains. Dumas also found 154 

 grains per hour as the average quantity of carbon exhaled by 

 an adult male. 



Scharling^s experiments were made on the following indi- 

 viduals : 1st, a male, set. thirty-five, weighing 131 lbs. ; 2d, 

 a male, set. sixteen, weighing 115ilbs. ; 3d, a soldier, set. 

 twenty-eight, weighing 164 lbs. ; 4th, a girl, set. nineteen, 

 weighing 11 U lbs. ; 5th, a boy, set. nine and three-quarters, 

 weighing 44 lbs. ; and 6th, a girl, set. ten, weighing 46 lbs. 

 The carbon exhaled per hour amounted to — 



9 



