On the Noji-existence of Sugar in the Blood. gj 



I have referred* secretion in general to the agency of the 

 electric power with which the nerves appear io be indued 

 and am thereby reconciled to the secretion of acid urine! 

 trom blood that is known to be alkaline, which before that 

 lime seemed highly paradoxical; and although the transfer 

 oi the prussiale of potash, of sugar, or of other substances 

 ihay equa ly be effected by the same power as acting cause, 

 still the channel through which they are conveyed remains 

 to be discovered by direct experiment. 

 • \''^^'u!. ''"'^'^^' conjectured that, bv examining the blond 

 m the abdominal vessels, or contents of the Jacieals, it mitrht 

 be possible to detect them in transitu; but I have not b?en 

 inchned to make such experiments on living animals, as 

 would perhaps throw light upon the subject. 

 f remain, dear sir, 

 with great regard, yours very truly. 



ia< 



Reply of Dr. Makcet on the same Subject. 



Russell Square, January 8, 18 !1. 



MvDEAuSiR,— T AM much gratified to find that you have 

 at last been inuuced to conimunicate to the Royal Society 

 your curious inquiry re>pectirig the state of the blood in 

 diabetes. 1 was anxious that the specious hypothesis of the 

 presence of sugar in diabetic blood, which had been sanc- 

 tioned by the authority of Dr. Rollo and Mr. Cruickshank 

 and which I had myself urged in support of (heir theory* 

 fourteen years ago, in an inaugural publication, should no 

 longer obtain an undue weight amongst physiological in- 

 quirers ° 



With regard to the experiments which I tried at your re- 

 quest some years ago, with a view to ascertain whether 

 prussiat of potash taken into the stomach, and found to exist 

 in the urine could also be detected in other secretions, I 

 find, on referring to my memorandums, the following par- 

 ticulars, which I shall transcribe verbatim. 



"August 19, 1807. Having heard from Dr. Wollaston, 

 |hat prussiat of potash could be taken into the stomach 

 with perfect safety, and that its presence could afterwards 

 he discovered m the nnne, but not in the serum ; and beinsj 

 invited by him to follow uj. this inquiry, with a view to 

 connect it with the theory of diabetes, I tried the following 

 jcxperiaienis. ^ 



• Phil. Mag. for June 1809. 



Experimeni 



