Part IL

The Materia Medina.

213

The ufes of fugar as a fweet,are fufficiently well known. Theimpure forts contain an un£tuous,or oily matter, in confeqirence ofwhich they prove emollient andlaxative. The cryltals are molldifficult of folution, and hence areproperelt where this foft lubricat-ing fweet is wanted to diffolveflowly in the mouth.

SAGAPENUM [L.EJ] a con-crate juice brought from Alexan-dria, either in diliinft tears, or runtogether in large maffes. It is out-wardly of a yellowifh colour, inter-nally foniewhat paler, and clearlike horn, grows foft upon beinghandled, and iticks to the fingers ;its tafle is hot and biting ; the Imelldifagretablr, by fome refembledto that of a leek, by others to amixture of afafctida andgalbanum.

Sagapenum is an ufeful aperientand deobliruent; and frequent-ly prefcribed either alone, or inconjundkion with ammoniacum, orgalbanum, for opening obltruc-tions of the vifcera, and in hy-ilerical diforders arifing from adeficiency of the menftrual purga-tions. It likewife deterges thepulmonary veffels, and proves ofconiiderable fervice in fome kindsof afthmas, where the lungs areoppreffed by vifcid phlegm. It ismolt commodioufly given in theform of pills: from two or threegrains to half a dram, may begiven every night or oftener, andcontinued for feme time. Whenfagapenum is fcarce, the druggiftsufually fupply its place with thel irger and darker coloured maffesof bdellium, broken into pieces ;which are not eafily diflinguifhedfrom it.

Sagapenum isan ingredient in thecompound powder of myrrh, gum-pills, elettary of bay-berries, mi-thridate and theriaca of the London

pharmacopoeia. The college ofEdinburgh has no where employedeither this gum or opoponax, giv-ing the perference to ammoniacuraand galbanum.

SAGO [£.] This is the pro-duce of an oriental tree, called byC. Bauhine patmnm referens arborfarinifera. The medullary partof the tree is beaten with water,and made into cakes, which areufed by the Indians as bread:tliefe reduced into granules, anddried, are the fago brought to us.It is moderately nutritious, thoughnot perhaps fupericr to our owngrain.

SAL AMMONIACUS. Sal

ammoniac [£.,/?.]

This is an artificial faline con-crete, faid to be prepared by fubli-maticn from the loot of cow dung.It is brought to us from Egypt, inlarge round cakes, convex on onefide, and concave on the other;and fometimes in conical loaves :on breaking, they appear compofedof needles, or iirise> running tranf-verfely. The belt are almolt trans-parent, colourlefs, and free fromany vifible impurities : thofe moltcommonly met with are of a greyyellowilh colour on the outfide,and fometimes black, according asthe matter is more or !efs impure.The tafte of this fait is very ftiarpand penetrating. It diffolves intwice its weight, or a little lefs, ofwater : and upon evaporating apart of the menflruum, concretesagain into long fhining fpicula, orthin fibrous plates, like feathers.

Sal ammoniac appears from ex-periments to be compofed of ma-rine acid, united with a volatile al-kali. If mingled with fixt falts, orabforbent earths, and expofed to 3moderate fire, a large quantity ofpure volatile faltfubljmes, the acid

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