ON VEGETABLE MUCII-AGES. g] 



In this case, however, I conceive that a proper precipitate corporate with 

 WHS formed, because a greater decree of opacity was percep- ^^' 

 tible, upon the additiun of alcohol to the mucilage, than 

 from an equal quantity of water ; and «^fter remaining for 

 some time, the effect was evidently increased, the solid mat- 

 ter being separated in a liocculent form. A turbidness was 

 produced upon adding the infusion of galls to the mucilage 

 of tragacanth, biit the same difficulty occurred in determin- 

 ing whether there was any speciiic effect produced by trie iStH^y 

 presence of the tan. I did not tind tragacanth to be preci- 

 pitated by the sulphate of copper, as stated by Dr. Dun- 

 can*. 



A well known vegetable mucilage is extracted from lin- ^^ucilsge of 

 seed. By adding a quantity of the seeds to 10 times their 

 weight of water, a fluid was procured of about the consist- 

 ence of the abumen ovi ; when poured from one vessel to 

 another it showed the same tenacity with the mucilage of 

 gum arable, and it also resembled gum in being indefinitely incorporates 

 soluble in water, and in immediately, incorporating itself ^^^''^^^^^'^^^k® 

 with any additional quantity of fluid. Its chemical properties . ' 

 are, however, considerably different from those of gum, its chemical 

 Upon the addition of the acetate of lead a copious, dense propemes. 

 precipitate was immediately thrown down ; with the super- , *^^ 



acetate of lead, and the nitro-muriate of tin, there was a 

 considerable opacity ; with the nitrate of mercury a slight 

 precipitate only was formed; while the nitro-muriate of gold, 

 the oxysulphate of iron, and silicated potash, produced no 

 effect. When equal parts of the mucilage and alcohol were 

 mixed, the fluid became slightly turbid, a degree of coa^^u- ^ 



lation was produced, and at length the solid matter was se- 

 parated in a flocculent form. Linseed mucilage is not pre- 

 cipitated by tan. 



A substance, which in its physical properties, and in the Mucilage of 

 manner in which it is procured, bears a strong analogy to quincesecd. 

 the linseed mucilage, is that^erived from the seeds of the 

 quince. A quantity of these seeds, boiled for a few mi- 

 nutes in 40 times their weight of water, produced a fluid of 

 about the same consistence with the linseed mucilage eai- 



♦ Ed. Dispensatory, p. 183, » 



ployed 



