THE PHEHOHENA OP HUMAN RESPIRATION. 
5 
Before entering any farther upon this comaiunication I must beg to acknowledge the 
valuable aid of my assistant, Mr. C. F. TowiM-SEND, F.C.S., to whose diligent, methodical, 
and careful work I am greatly indebted for tlie results obtained in the present inquiry. 
We made too^ether the numerous calculations for the reductions, tlms checkinof the 
figures in every possible way to insure accuracy. 
Since my attention was first given to the chemical phenomena of respiration, I have 
had the honour of communicating to the Boyal Society a succession of papers on the 
“ Influence of Altitude on Respiration,” which have appeared in volumes 27, 28, 29, and 
31 of the ‘ Proceedings.’ These inqumies show in the most conclusive manner that alti¬ 
tude exerts an action on respiration depending exclusively on the fall of atmospheric 
pressure, and the law can be expressed as follows:—“The volumes of air breathed, 
reduced to 0° and 760 mm., in order to produce a certain weight, say, 1 gramme of 
carbonic acid in the body, are smaller on mountains under diminished atmospheric 
pressures than they are in the plains under higher pressures.” My earliest experiments 
on the Breithorn (13,685 feet—4171 metres), the Col St. Theodule (10,899 feet—3322 
metres), the Riffel (8428 feet—2568 metres), the St. Bernard (8115 feet—2473 metres), 
and the Col du Geant (11,030 feet—3362 metres) were all attended with a fall of the 
atmospheric temperature on reaching into higher altitudes; this circumstance neces¬ 
sarily produced an increased combustion in the body in order to overcome the action 
of the cold, and introduced an element into the inquiry winch was likely to interfere 
with the exclusive influence altitude might exert on the chemical phenomena of 
respiration. The only way of overcoming this difficulty was to resort to a mountain 
where it was possible to ascend to a considerable altitude without meeting wuth the 
cold air of noi'thern Alpine districts. Thus I was induced to visit the Peak of 
Tenerife, taking with me the instruments required to repeat the experiments under¬ 
taken in the Swiss Alps. I spent three weeks on the Peak in the summer of 1878, 
engaged in these inquiries. The temperature, though varying somewhat at the three 
stations I had selected at various altitudes, was always hot in the daytime, and there 
was no cause for any increased formation of carbonic acid in the body towards the 
resistance of cold. The result was most striking. While in the cold Swiss Alps I 
had observed an increased expiration of carbonic acid when ascending on myself and 
otffiers who submitted to the experiment, on the Peak of Tenerife there was no such 
increase. The mean weight of carbonic acid expired at the three stations by two 
different persons was, with one exception at one station only—in the case of a 
Chamonix guide—nearly the same for each of them respectively ; the volumes of air 
breathed were lessened,”" so that the law remained unchanged : that at increasing alti- 
* There is one exception in the case of the Chamonix guide, the volume of air he expired (for 1 grm, 
COj) being somewhat greater at the higher than the intermediate station on the Peak; but the mean 
volume of air expired at these two stations, taken collectively, was much less than the mean volume of air 
expired .at the seasidi*. 
