and some other Animal 'Fluids. 1 1 5 



tion of dilute sulphuric and muriatic acid ; but alcohol pro- 

 duced no effect. 



From the result of these trials, it might have been con- 

 cluded that gelatine was taken up by the water; but as an 

 alkaline sokiVion of albumen forms an imperfect jelly when 

 duly concentrated, and as albumen and gelatine are both 

 precipitated bv tannin, I was inclined to put little reliance 

 on the appearances just described, until I had examined the 

 solution by the n)ore accurate method of electrical decom- 

 position. 



Upon placing it in the Voltaic circuit my suspicions 

 were justified, bv the rapid coagulation which took place 

 in contact with the negative wire. I therefore made some 

 other experiments in order to corroborate this result. 



One fluid ounce of pure serum was dissolved in three of 

 distilled water : the conductors from a battery of thirty 

 pairs of four-inch plates were immersed in this solution at 

 a distance of two inches from each other; the electrization 

 was continued during three hours and a half, the solid al- 

 bumen being; occasionally removed : at the end of that 

 period, no further coagulati<m took place, and a mere de- 

 composition of the waler was going on. 



Having ascertained in previous researches, that gelatine 

 is not altered during the electrical decomposition of its so- 

 lution carried on as just described, my object in this ex- 

 periment was, "to ascertain whether any gelatine remained 

 after the comple'e separati'.;n of the albumen had been ef- 

 fected. I accordingly examined the waler from which the 

 coagulated albumen had been removed, and found that it 

 wasnot altered by infusion of galls, nor did it afford any 

 gelatine when evaporated to dryness. 



l\vo fluid ounces of dilute muriatic acid were added to 

 one of serum. The mixture inmiediately assumed a gela- 

 tinous appearance ; it was heated, and a more perfect co- 

 awulaiion of the albumen took place; the liquid part was 

 separated by a filter. No effect was produced upon it by 

 Voltaic electricity, nor did infusion of galls occasion any 

 precipitaticm. 



I repeated the first experiment with the addition of twenty 

 drops of a solution of isinglass to the serum. The liquid 

 which now separated, after the albumen had beerL entirely 

 ■cr)agulaled by the action of electricity, was copiously pre- 

 cipitated by infusion oF galls. 



It may be inferred Irom these experiment?, that gelatine 



does not exist in the serum of the blood, and that the se- 



rositv consists of albunicn in combination with a large pro- 



H 2 portion 



