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CHAPTER III.

Infujions in different menjlrua.

SECT. I.

Infujions and decoctions in water.

WATER, the direfl men.ftruum of gums and falts,extrafts readily the gummy and fa-line parts of vegetables. Its ac-tion however, is not limited tothefe; the refinous and oily prin-ciples being, in molt vegetables, fointimately blended with the gum-my and faline, as to be in greatpart taken up along with them :fome of the refinous cathartics, andmoll of the aromatic herbs, as wellas bitters and aftringents, yield towater greatell part of their fmell,tafte, and medicinal virtue. Evenof the pure eflential oils, and odo-rous refins of vegetables, feparatedfrom the other principles, waterimbibes a part ©f the flavour; andby the artificial admixture of gum-my or faline matter, the whole fub-ftance of the oil or refin is madedifloluble in water.

Of pure falts, water diflolves on-ly certain determinate quantities(fee page 39): by applying heat,it is generally enabled to take upmore than it can do in the cold,and this in proportion to the degreeof heat; but as the liquor cools,this additional quantity feparates,and the water retains no more thanit would have difl'olved withoutheat. With gummy fubftances, onthe other hand, it unites unlimit-edly, diffolving more and moreof them till it lofes its fluidity:keat expedites the station of the

water, but cannot enable it to takeup more than it would do, by al-lowing it longer time, in the cold.The adlive parts extra&ed frommod vegetables by water, and oilsand refins made foluble in water bythe artificial admixture of gum,partake of this property of puregums, being difloluble withoutfaturation.

It has been imagined that veget-ables in a frelh ftate, while theiroily, refinous, and other attiveparts, are already blended with awatery fluid, would yield their vir-tues to water more freely and moreplentifully, than when their nativemoifture has been dillipated by dry-ing. Experience however Ihews,that dry vegetables, in general,giveoutmore than frelh ones, waterfeeming to have little aftion uponthem in their recent Itate. If, oftwo equal quantities of mint, onebe infufed frefh in water, and theother dried, and then infufed in thelike quantity of water for the famelength of time, the infufion of thedry herb will be remarkably theItrongefl:: and the cafe appears tobe the fame in all the vegetablesthat have been tried.

In all the preparations defcribedin this chapter, it is to be under-ilood that the fubjefts mull be mo-derately and newly dried ; unlefswhen they are exprefsly ordered tobe taken frelh; in which cafe it is^o