288 Chapter XIX 



clinical adjective ; and I will write it down here in the terms in which 

 I think of it " Lewis's dyspnoea." 



Nevertheless there are certain broad aspects of these cases which 

 seem to justify some comment. The prevalence of acids in the blood 

 coupled with the absence of acids which are abnormal in kind suggests 

 that the condition is due rather to renal than to metabolic disturbance. 



Had we found excess of lactic we might have supposed that there 

 was general oxygen want in the tissues, had we found /8-oxybutyric 

 we might have tried to link the condition with metabolic disorders, 

 but the evidence so far as it goes is that the kidneys, instead of 

 keeping the blood at a certain composition which we call normal keeps 

 it at another and more acid character which we call abnormal. Such 

 a change might be wrought by a functional renal disturbance so slight 

 as to be quite remote from the region of a visible lesion of the kidney. 



The analogy between the condition which we have been discussing 

 and the condition of the body at altitudes of about 10,000 ft. is in- 

 evitable. Meionexy, fall in alveolar C0 2 pressure, increase in acid 

 character of the blood, are the obvious points of resemblance. 



In each case the immediate cause of the change in the blood 

 seems to be renal, beyond this we cannot at present go. 



In our study of the cases of Lewis's dyspnoea we compared them 

 with various other cases which served as controls. In addition to 

 cases of dyspnoea referable to evident cardiac trouble such as E. M., 

 we compared cases of " Lewis's dyspnoea " with ones which had no 

 dyspnoea but were in hospital for quite other reasons such as con- 

 valescent appendix or gastric cases. In these we found the value of 

 K to be singularly constant, much more so than in the case of persons 

 living an everyday life. This no doubt was due to the fact that these 

 control cases were all of middle age or rather more and were living 

 the same sort of life and eating the same sort of diet. The value of K 

 varied from '00024 to '00034, being thus higher than in the cases of 

 dyspnoea from whatever cause they arose. 



But the most interesting controls were those of the patients 

 suffering from "Lewis's dyspnoea" whose condition changed con- 

 siderably whilst they were in our hands. 



For instance one case J. P. was seen by me first on February 14, he 

 was then suffering from the complaint, a month later he was sufficiently 

 well to be discharged; just before this I saw him on March 13th. 

 Within a month (April 7) he returned in a very grave condition and 

 died that evening. The day before his death his blood was tested again. 



