NONF.XfSTSNCE OP 9UG1R IN DIABETIC BLOOD. J^^ 



had taken tyiirteen or fourteen such doses. After the fifth 

 dose, her urine, by the addition of a drop or two of a solu- 

 tion of sulphate of iron, turned blue instantly. At this pe- 

 riod of the experiment, a blister was applied to her stomach, 

 and after a few hours, while still taking the prussiute of pot- 

 ash, and while the urine strongly indicated its presence, the 



blister was cut, and the serum collected. This serous fluid ^^^"*^ '" *^® 

 . . . , , . , • , , serum from a. 



oem^t m the same manner as the nrme, subjected to the blister. 



section of a solution of sulphate of iron, did not suffer any 

 change of colour in the least indicalive of the presence of 

 prussic acid. Yet the urine still remained capable of im- 

 parting a blue colour to solution of iron, fifteen hours after 

 taking the last dose of the prussiate of potash. 



£!xp. 'i. ** The same person being soon afterward out^'^P''- 

 upon a course ot terrugmous medicines, and havmg taken ^on takeu, 

 considerable quantities of snljihate of iron, an idea naturally 

 occurred to me, that the phenomenon might perhaps be 

 reversed ; but upon adding prussiate of potash to the urine. No iron in ihe 

 no vestige of iron could be discovered, and the same attempt 

 "«Tas repeated several times with the same negative result. 



JExp. 3. " Dec. 2, I8O7. The fluid obtained by means Exp. 3. 

 of a blister (as in Experiment 1,) being not immediately 

 derived from the circulation, since it may be considered as 

 the product of a secretion, 1 was desirous of repeating Dr, 

 Wollaston's experiment on the serum itself, under circum- 

 stances of impregnation similar to those, in which the serum 

 of the blister was examined. 



** For this purpose, a young woman, after taking, in divl- Prussiate of 

 ded doses, about a dram of prussiate of potash in the course ^^ ^^ \^^^ 

 of twelve hours, lost some blood by cupping, an operation urine, but 

 which had been ordered for a local complaint under which "^rVm ofthe 

 she laboured. The serum having been allowed to separate, biocd, 

 and a little nitric acid having been added to it, not the least 

 vestige of prussic acid appeared on applying the test of sul- 

 phate of iron, although the urine, made during the six hours 

 which preceded and ioUowed the cupping, was strongly im- 

 pregnated with that acid, and struck a vivid blue upon ad- 

 ding the smallest quantity of iron." 



I have only to observe, in addition to these particulars, Prussiate of 

 that the susceptibility, by which prussiate of potash is trans- ^onve^ ed\o 



mitted 



