com-* 

 wa- 



184 NONEXISTENCE OF SUGAR IN DIIBETIC BLOOD. 



pletely coc-ulafed, and by what appearances the presence 

 of sugar that had been addtd to it wpuld be most easily 

 discerned, 



hl'lcrumTo? ^*'^" ^^""^ ^^°"^ ^^^ ^''^" employed for the coajrulation 



conipletelv of serum, to which water had been added, t]j;.it which ex- 



coagulattd byudedfromit was still found to contain a portion ofalbu- 



* men dissolved in it ; and if this were allowed to remain, any 



saccharine matter which might be present would be disguised, 



and could not with certainty be detected. 



unless a small I f'ouiid, however, that this residuum ov ooa^^ulable matter 



portion of di- • , , , , ^ 



lute acid was "^'8'^* '^^ altogether prevented by the addition of a small 



previously quantity of dilute acid to the serum before coagulation*. 



To six drams of serum 1 added half u dram of muriatic acid 



previously diluted with one dram and a half of water, and 



immersed the phial containing them in boiling water during 



four minutes. The coagulation was thus rendered 



plete. In the course of a few hours a dram or more of 



' ■ ^«'* exudes from serum that has been so coagulated. Jf a 



Salt irt the se- drop of this water be evaporated, the salts which it eontains 



^"»"- are found to crystallize, so that the form of the crystals 



may be easily distinguished ; they are principally common 



salt. 



Effect of the If any portion of saccharine matter has been added to the 



presence of • , , . . 



sugar. ^^"""^ previous to coagulation, the crystallization of the 



salts is impeded, or wholly prevented, according to the 



quantity of sugar present. 



If the quantity added does not exceed two grains and a 

 hJilf to the ounce, the crystallization is not prevented; but 

 even this small quantity is perceptible by a degree of 

 blackness, that appears after evaporation : occasioned, as [ 

 suppose, by the action of a small excess of acid on the 

 sugar. 



If five grains have been added, the crystallization is very 

 imperfect, and soon disappears in a moist air by deliqui-o- 

 cence of the sugar. The blackness is also deeper thjm ia 

 the former case. 



* I presumed, that this portion of albumen was retained in solution by 

 the alkali redundant in serum, and added the acid for the purpose of 

 neutralizing it. 



By 



