710 INFLUENCE OF CLIMATE ON THE 



F.* (Experiments and Observations on Animal 

 Heat, pp. 311, 387.) 



Now if these experiments are to be relied on, 

 and the first of them be taken as a standard, it 

 follows that respiration is diminished 1 00 per cent, 

 by elevating the temperature of the air 48, which 

 is the difference between 55 (omitting fractions) 



* In the Memoirs of the French Academy of Sciences for 1789 

 are recorded some experiments performed by Lavoisier on M. 

 Seguin, a vigorous young man, who consumed 1344 cubic inches 

 of oxygen per hour, when surrounded with air at 59, and 1210 

 cubic inches, when supplied with air at 91. From which it 

 would appear that respiration was diminished only 10 per cent, 

 by elevating the surrounding air 32, or from 59 to 91, which 

 is about the difference between the temperature of London or Paris, 

 and that of the tropics. It also follows from these results, that 

 the average amount of respiration is only 25*62 per cent, greater 

 in polar America than within the tropics, and 62-5 per cent, more 

 at 70 below 0, than at 130, as when exposed to an African sun. 

 And as the density or sp gr. of elastic fluids is diminished 100 per 

 cent, by 480 of heat, (see p. 103,) it follows that the same volume 

 of oxygen would weigh 6-66 per cent, more at 50, (the mean tem- 

 perature of London) than at 82; and 17 per cent, more at 0. 

 Corresponding with these facts, it has been observed by the manu- 

 facturers of iron in Europe and the United States, that more ca- 

 loric is obtained by ordinary combustion during winter than sum- 

 mer, especially when the air is sultry and saturated with vapour, 

 which carries off a large amount of caloric in a combined or latent 

 state ; and that a larger amount of fuel is required to perform the 

 same duty, than when the air is cold and dry. It is not true, how- 

 ever, that sun shine puts out a common fire, as the vulgar sup- 

 pose, but it is rendered invisible or obscure by the superior lustre 

 of the sun. Yet Dr. M'Keever found that in a dark room at 63, 

 one inch of a common candle was consumed in fifty-six minutes, 

 but required fifty-nine minutes in strong sun shine at 80. 



