|C2 KONEXISTENCE OF SUGAR IN DIABETIC BLOOD; 



thebladdej in mitted to the bladder, seems to vary in different individuals; 

 all persons f^,. j^, g^^ ^^.^.^^^ ^a^j^ at Gwy's Hospital in Nov. 1805, I 

 vfitli the same , . . . „ ! . 



facility. failed of discovering any vestjcre or this salt in the urine of 



persons, who had taken it in quantities snfficient to produce 

 its appearance in others. Three of these rndividuals, I 

 should observe, were at the time under mercurial treat- 

 ment ; and an idea occurred to me, that, mercury having a 

 great affinity for prussic acid, the presence of this metal in 

 the system mi«rht prevent the effect in question. But, as ia 

 the two other failures no mercury was present, I cannot lay 

 Jio :iiconveni- any stress upon this conjecture. It may be proper to men- 

 encefrom ^-^^^ ^^^^ -j^ jj^^ frequent trials which I have made with the 

 taking u. • f. , 



prusbiate ot potash, no symptom or mconvenience whatever 



has ever occurred, which could be ascribed to this salt. 

 I remain ever. 



My dear sir, with great esteem. 

 Yours sincerely, 



ALEX. MARCET. 



The channel p. S. While revising the proof of this sheet, it has been 

 may be the observed to me by some friends, and in particular by Dr. 

 arteries and Henrv of Manchester, and Dr. R. Pearson of London, 

 Ib^xcSr t^^at, in order to show distinctly that certain substances find 

 oi the vein*, their way to the bladder, without passing through the gene- 

 ral circulation, it would be necessary to examine the arterial, 

 as well as the venous blood, since it is not impossible, that 

 the whole of the sugar in diabetes, or the prussiate of pot- 

 ash in the experiments above related, may be conveyed to 

 the urinary organs by the arteries, without entering the ve- 

 nous system. According to this hypothesis, it may be con- 

 ceived, that the same substances, when conveyed by the ai:- 

 teriesto distant parts of the body, may return by the ab- 

 sorbent system, and might in this case be discovered in the 

 thoracic duct. This view of the subject may deserve farther 

 investigation ; and 1 hope, that this curious question will 

 sopn ^e decided by appropriate experiments. 



VJ. 



