226 Dr. W. Marcet on the Function of Respiration at [June 19* 



Table IV. — Slow Breaking of Iron Wire, "036 inch in diameter, at 

 various speeds. " Bright Annealed Wire." 



Xumber of 

 experiment. 



Rate of adding 

 weight. 



Breaking "weight 

 in pounds. 



Per cent, of 

 elongation on 

 original length. 



1 



1 lb. per 24 hours 



47 



6-92 



2 





47 



4-79 



3 



i 



2 3> JJ 



46| 



6-00 



I have to acknowledge the very great assistance rendered to me in 

 the carrying out of these experiments by Mr. Sinclair Conper, who has 

 not only most faithfully carried out the work entrusted to his charge, 

 but has in many cases originated and earned out experiments at 

 various points of the inquiry. 



XXII. " Note on the paper (read April 24}* 'A Summary of an 

 Inquiry into the Function of Respiration at A^arious Alti- 

 tudes on the Island and Peak of Teneriffe/'' By WILLIAM 

 Marcet, M.D.. F.R.S. Received June 16, 1879. 



In the above-stated communication, after alluding to Dr. Rattray's 

 observationsf and remarking that I had formerly held the same views 

 as he did, namely, that less carbonic acid was exhaled under in- 

 creasing tenrperatures of the sun ; I add, I am now compelled, how- 

 ever, to alter this view, and to conclude that more carbonic acid is 

 formed in the body under a tropical or nearly tropical sun than under 

 temperate latitudes. 



Lest I should be considered as ascribing to the sun's heat a power 

 which so far has not been acknowledged by physiologists, namely, 

 that of increasing the formation of carbonic acid or the combustion 

 in the body, I must beg to explain in a few words how the question 

 now stands. I shall end by asking leave to suspend any opinion as 

 to the cause of the increase of combustion in the body I observed to 

 take place on the Island of Teneriffe. until more direct experiment 

 has been brought to bear on the subject. 



From trustworthy experiments by known authors, heat and light 

 are found to act differently with respect to the formation of carbonic 

 acid in the animal and human body ; increased heat, as a rule, 

 diminishes the production of this gas, and it is generated in excess 

 under increased light. 



* " Proc. Roy. Soc," vol. xxviii, p. 498. 

 f 11 Proc. Roy. Soc.," 1870, 1871.. 1873. 



