94 SCIENCE PROGRESS. 



Indeed, heart-failure which cannot be distinguished from 

 true mountain sickness may occur at the sea level. The 

 point we have to consider, then, is how far Conway's obser- 

 vations and pulse-tracings indicate whether or not, while 

 suffering from true mountain sickness, there was also heart- 

 failure. 



I give here reproductions of the pulse tracings of 

 Conway and his party, taken at different altitudes, having 

 chosen twenty-one of the total twenty-seven curves which 

 have been submitted to me, those omitted being taken at 

 lower levels than those shown, and being therefore of less 

 interest in the present connection. The letters to the left 

 of the figures show from whom each tracing was ob- 

 tained, and the numbers give the pulse-beats per minute, 

 which I have calculated from the rate of movement of the 

 clockwork used to move the paper past the point of the 

 recording lever. The descriptions to the right of the 

 figures are Conway's notes. I will analyse the tracings 

 briefly, without seeking to confine my remarks to the 

 question as to whether they do or do not indicate that 

 heart-failure is an essential element in mountain sickness, 

 and I make allowance for the inaccuracy of the sphygmo- 

 graph employed. 



Of the curves in Fig. i, Conway's and McCormick's 

 are ordinary tracings, such as one usually obtains from healthy 

 men with a Dudgeon's sphygmograph, and the pulse-rate 

 is within the usual limits of quiet life. Roudebush's and 

 Eckenstein's show a more rapid beat, with the change in 

 the form of the pulse-wave which usually goes with it. 



Fig. 2 shows that the four members of the party were 

 fatigued, the quick pulse rate in the absence of fever 

 indicating a demand by the tissues for more blood. I 

 cannot go over the reasons which exist for believing that 

 the " nervi accelerantes cordis" have for their function to 

 increase the force and frequence of the heart in response 

 to demands of the rest of the body for more nutriment (4), 

 and need only note that the form of the curves corresponds 

 with the increased rate of heart-beat. It can be seen, 

 however, that at the elevation of 14,000 feet the hearts of 



