Some clinical aspects 283 



Schlayer and Straub's paper, in which they described the low 

 alveolar pressure of CO 2 in uraemic cases, bore the title " Is uraemia 

 an acidosis? " The answer to that at the present time, in so far as it 

 can be given, is as follows. It is not a lactic acidosis, yet the change 

 in the value of K in the equation 



y Kx n 



Too ~ = i 



is such as would be produced by the addition of acid to the blood, 

 and as far as is known this change can be produced in no other way. 

 The addition of urea to the blood does not reduce the value of K. 

 Uraemia therefore is accompanied by a change in the reaction of the 

 blood in the acid direction. This change is not due to excess of C0 2 

 but to excess of other acids. In this sense it is an acidosis. 



Now to turn from uraemia to the class of cases on which I myself 

 have worked. I came upon them in this way. Dr Thomas Lewis, 

 Physician to University College Hospital, London, told me of certain 

 cases of dyspnoea in which the distress was unaccompanied by 

 cyanosis or other physical signs of a sufficiently grave character 

 to account for the degree of dyspnoea. In the absence of sufficient 

 physical signs he inquired if there were chemical signs to which the 

 dyspnoea could be attributed. After a few preliminary experiments 

 we determined to make an investigation on the following lines. 



Lewis undertook the selection of cases and their treatment ; Ryftel, 

 the estimation of lactic acid in the blood and of abnormal organic 

 acids in the urine ; Wolf, the analysis of the blood for urea, ammonia 

 and " rest " nitrogen ; Cotton, the analysis of the blood for urea 

 (hypobromite) and the determination of the constant of Ambard* ; 

 whilst the tests for meionexy and acidosis and the alveolar air deter- 

 minations were undertaken by me. 



The reader will get the most clear account of these cases of 

 dyspnoea by reading the reports on a typical case. From these he 

 will see that there is : 



(1) Considerable acidosis (in the sense in which I have defined 

 the word). 



(2) Low alveolar C0 2 and respiratory quotient. 



(3) Meionexy. 



It is clear then that the dyspnoea is explained : there is no further 

 mystery about it. The meionexy sufficiently accounts for it. 



* See Appendix IV. 



