G17ZARD OF FOWLS. HOP 



Hence it refults, that the greater part of the falts contained 

 in gizzard, is the acid phofphate of lime ; the prel'ence of 

 muriate and fulphate of potafli is alfo obfervable. 



Thefe falts are not only united with gelatine, but alfo with 

 a fmall quantity of extra6tive matter. It (liould feem that the 

 latter fubftance, and perhaps the gelatine, is oxigenated by 

 the deficcation of the gizzard ; for in this Rate lliey are lefs 

 foluble in water, 



Wifliing to afcertain the difference between pure gela- 

 tine, and that which had been oxigenaled, I made ex- 

 periments upon the former, of which the following is the 

 refult. 



Pure gelatine acquires different properties, according to the Experiments on 

 means employed in its oxigenation. gelatin. 



Of the metallic oxides, fome freely communicate their with metallle 

 oxiged to gelatine, as the oxide of red-lead, and the red oxide °^"^"* 

 of mercury ; but the gelatine was combined with a part of 

 the oxide, and could not again be feparated completely from 

 it. In treating gelatine with the red oxide of mercury, a 

 part of the oxide was reftored to its metallic Hale, and the 

 remainder affumed a reddifli brown colour. 



Superoxigenated muriate of potafli heated witli gelatine. And other 



caufed no alteration in its nature. '"'f ' °^ "'^se* 



nation. 

 Oxigen gas combined with it but flowly, and in fmall 



quantity. After being for a confiderable time fubmitted to 



the a6tion of this gas, the gelatine only luffered a change of 



colour; it became whitifti, but its charaiSterifiics are flill the 



Tame. 



Oxigenated muriatic acid prefented the following pheno- 

 mena. 



On pouring oxigenated muriatic acid gas into diffolved ge- 

 latine, a whitith thick fcum appeared on the furface, of a / 

 moderate thicknefs, the under fide of which gradually changed 

 colour, and became milky. The white filaments which fwam 

 in the liquor, together with the fcum which floated on the 

 furface, were feparated by filtering, and waflied In cold and 

 warm water till the water ceafed to redden tincture of turnfol. 

 The fubftance thus prepared prefented the following cha- 

 ra6leriftics : 



1, It was capable ofextenfion equally with gluten, and was Properties of 



Qf a white colour. oxigenated 



2. It^=^^^'"- 



