•d On the Non- existence of Sugar in the Blood. 



Experimetit 1. — " After having satisfied myself, by trials 

 made bv some medicJil gentlemen upon themselves, that 

 cnns'iderable doses of priissiat of potash might be taken 

 without the least inconvenience, T gave to a young woman 

 labouring under diabetes mellitus, five grains of prussiat of 

 potash dissolved in water, and this was repealed every hour 

 till she had tikcn thirteen or fourteen such doses. Atter 

 the fifth dose, her urine, by the Addition of a drop or two 

 of a solution of sulphat of iron, turned blue instantly. At 

 this period of the experiment, a blister was applied lo her 

 stomach, aud after a few hours, whilst still taking the prus- 

 siat of potash, and whilst the urine strongly indicated its 

 presence, the blister was cut and the serum collected. This 

 serous fluid being, in the same manner as the urine, sub- 

 j-ected to the action of a solution of sulphat of iron, did not 

 suftlr any change of colour in the least indicative of the 

 presence of prussic acid. Yet the urine still remained ca- 

 pable of imparting a blue colour to a solution of iron, 15 

 hours after taking the last dose of the prussiat of potash. 



Experiment 2. — "The same person being soon after- 

 wards put upon a course of ferruginous medicines, and 

 having taken considerable quantities of sulphat of iron, an 

 idea naturally occurred to me that the phaenomenon might 

 perhaps be reversed ; but upon adding prussiat of potash 

 to the urine, no vestige of iron could be discovered, and 

 the same attempt was repeated several times with the same 

 negative resnlt. 



Experiment 3. — " Dec. ^?, 1S07. The fluid obtained 

 by means of a blister (as in Experiment 1,) being not im- 

 mediately derived from the circulation, since it may be con- 

 sidered as the product of a secretion, I was desirous of re- 

 peating Dr. WoUaston's experiment on the stjrum itself, 

 under circumstances of imprciination similar to those in 

 which the serum of the blister was examined. 



" For this purpose, a young woman after taking, in di- 

 vided doses, about a drachm of prussiat of potash in the 

 course of twelve hours, lost some blood by cupping, an 

 operation which had been ordered for a local complaint! 

 luider which she laboured. The serum having been allowed 

 to separate, and a little nitric acid having been added to it, 

 not she least vestige of prussic acid appeared in a|)plying 

 the test of sulphat of iron, although the urine made during 

 the six hours Vv'hich- preceded and followed the cupping, 

 ■w-as strongly impregnated with that acid, and struck a viyid 

 blue upon adding Xhn smallest quantitv of iron." 



I have 



