368 Miscellanies. 



The experiments of Mr. Coathupe, were many times repeated upon 

 other individuals and always accorded with the average results already 

 stated. 



General conclusions. 



1. The average respirations by most adult individuals, varying between 

 17 and 20 per minute, may be stated at 20 per minute. 



2. The average bulk of air, varying between 14 and 18 cubic inches, 

 may be stated at 20 cubic inches. 



3. The average production of carbonic acid gas in human respiration, 

 varying between 1.9 and 7.98 per cent., may be stated at 4 per cent. 



Hence 460.800 cubic inches, or 266.66 cubic feet of air respired by a 

 healthy adult, of average stature and heahh in 24 hours, of which 10.666 

 cubic feet will be converted into carbonic acid = 2386.27 grains, or 5.45 

 avoird. ounces of carbon. 



This gives 99.6 grains of carbon per hour by one human adult, or 

 124.328 pounds annually. The population of Great Britain and Ireland 

 26|- millions, emit 147.070 tons of carbon annually. 



The maximum quantity of air requisite for a healthy adult during 24 

 hours, (even supposing that no portion of the air was inspired twice,) will 

 not exceed 266.666 cubic feet. For the proofs of these important con- 

 clusions we must refer to their very valuable memoir already cited ; it 

 occupies 14 pages 8vo., with a large proportion of figures and tables. — 

 Eds. 



40. Chemical Equivalents. — Richard Phillips, Esq., F. R. S., in a pa- 

 per read to the Royal Society on the chemical equivalents of certain 

 bodies, concludes that " no material and even scarcely any appreciable 

 error can arise from considering the equivalent numbers of hydrogen, 

 azote, and chlorine, as being 1, 8, 14 and 36 respectively." 



It is most desirable to be freed from the necessity of introducing frac- 

 tions into the numbers representing chemical equivalents. — Land, and 

 Edin. Phil Mag., May, 1839. 



41. Photogenic power of Light from burning CoJce. — Mr. Robert 

 Mallet has discovered that the light emitted by incandescent coke black- 

 ens photogenic paper in about forty five seconds ; a property possessed in 

 a sufficient degree by few artificial lights. The author discovered a con- 

 siderable time since that the light emitted by incandescent coke at the 

 twyer of a cupola furnace contains the chemical rays in sufficient abun- 

 dance. It is supposed that there will be no difficulty in burning a small 

 quantity of coke at a high temperature, and that the light may be made 

 use of to register nocturnal observations. — Id. 



