414 Dr. Thomson and Mr. Richardson on the 



From my own observations, and from the experiments of 

 others, the following details connected with this subject may 

 be faithfully relied on, viz. 



1st. The average number of respirations made by most adult 

 healthy individuals (varying from 17 to ^3 per minute) 

 may be stated as 20 per minute. 

 2nd. The average bulk of air respired at each respiration 

 made by such individuals (varying from 14 to 18 cubic 

 inches) may be stated as 16 cubic inches. 

 3rd. The average daily amount of carbonic acid gas found 

 in the air respired by such individuals (varying at its 

 extremes from 1*9 to 7*98 per cent.) may be stated as 

 4 per cent. 

 Hence 460800 cubic inches, or 266'66 cubic feet of air 

 pass through the lungs of a healthy adult of ordinary stature 

 in 24 hours, of which 1 0*666 cubic feet will be converted into 

 carbonic acid gas, = 2386*27 grs. or 5*45 ounces avoirdupois, 

 of carbon. 'I'his gives 99*6 grs. of carbon per hour, pro- 

 duced by the respiration of one human adult, or 124*328 

 pounds annually ; and if we multiply this by 26- millions 

 (being the calculated population of Great Britain and Ireland 

 for the year 1839) we have 147,070 tons of carbon as the 

 annual product of the respiration of human beings at present 

 existing within the circumscribed boundaries of Great Britain 

 and Ireland. 



Hence also the maximum quantity of fresh atmospheric air 

 that can possibly be I'equired by a healthy adult during 24 

 hours, even supposing that no portion of the air respired 

 could be again inspired, will not exceed 266*666 cubic feet. 



Wraxall, near Bristol, CharLES Thornton CoathuPE. 



Feb. 1839. 



LXI. On the Decomposition of Amygdalin by Emulsin. By 

 Robert D. Thomson, M.D., and Mr. Thomas Richard- 

 son.* 



COME years ago Robiquet aud Boutron-Charlard showed 

 ^ that volatile oil of bitter almonds and prussic acid, which 

 are obtained by the distillation of bitter almonds, do not exist 

 naturally in the almonds but result from the pi'ocess. They 

 further ascertained, that when milk of bitter almonds, formed 

 by triturating almonds with water in a mortar is treated with 

 strong boiling alcohol, on cooling white crystals are depo- 



* From the Annalcn der Pharmacie, Band xxix. Heft 2n(l, Feb. 1839; 

 and communicated by Mr. Richardson. 



