32 ON VEGETABLE MUCILAGES. 



-m 



ployed in the last experiments. When poured from one 



vessel to another, it exhibited tlie same deoTPo of tenacity ; 



when recent it was perfectly homogeneou^', but after being 



kept for some time, it shoM'ed a tendency to coagulation. It 



Coagulated by was submitted to the same reagents as in the former experi- 



most of the re- ^ j -.t i, ^ t , . . , 



agents. ments ; and with all of them, except the sihcated potash 



and the galls, the efiect produced was a greater or less de- 

 - ^ gree of coagulation. With the acetate of lead the coagu- 

 1^ lation was so considerable, tiiat the solid matter was in- 

 stantly precipitated in the form of dense white flakes; the 

 eft'ect was equally rapid with the nitro-niuriate of tin, but 

 the coagulum was not in quite so dense a state. With the 

 superacetate of lead, the nitro-muriate of gold, the nitrate 

 of mercury, and the oxysulphate of iron, the coagulation 



Coagulable by was less complete, although sufficiently a|>parent. As the 

 quince niucilage is coagulated by the mere addition of an 

 acid, it is probable, that the effect produced in these cases 

 may depend in some degree upon the acid, which enters 



but this does iwto the composition of these metallic salts ; yet the action 



rot account ^f j-j^^ acetate of lead and the nitro-muriate of tin were so 

 for the effects. . . 



remarkable, as to indicate the operation of a specific affi- 



Tiity. It may be farther observed, that a greater effect is 

 produced by the acetate of lead, than by the super-acetate, 

 although in this latter salt there is a portion of uncombined 

 acid. The effect of alcohol upon the quince mucilage was 

 exactly similar to that upon the linseed. 

 Hyacinth roots The bulbous roots of many vegetables are composed in a 

 great measure of mucilage, upon which I proposed to make 

 my next experiments, and for this purpose I selected the 

 hyacinth. Some of the roots of the common blue bell*, 

 were bruised in an earthen mortar, and afterward rubbed 

 with four times their weight of water. The whole was con- 

 verted into a pulpy mass, which was strained through linen, 

 and then appeared homogeneous, although opake. In a 

 few hours a substance of a farinaceous appearance separated 

 from it, and left the mucilage more transparent. It was 

 now filtered through paper, and w as in appearance and con- 

 sistence very similar to the mucilage of linseed; although it 



* Hyacinihus non sciiptus of Withering, scilla nutans of Smith. 



* ' ^ differed 



