VOL. L.] PHILOSOPHICAL TRANSACTIONS. Ml 



teals seem to be endowed with that admirable faculty of admitting such particles 

 of pure chyle as they happen to be in contact with, and of accommodating their 

 diameters to them, at the same time that by their natural irritability, and power 

 of constriction, they obstinately exclude such as are astringent ; which, were 

 they to enter the lacteals, would either produce dangerous obstructions in these 

 vessels, or if they got into the blood, would occasion polypous concretions in the 

 larger vessels, or coagulations incapable of being transmitted through the minute 

 vessels of the lungs ; the effects of which would be either sudden death, or at 

 least inflammations and suppurations from obstructions in the pulmonary vessels; 

 inconveniences which nature, by precluding astringents from entering the lac^ 

 teals, has carefully and wisely avoided. 



Salt of steel, taken internally, must retain its astringency until it be precipi- 

 tated : which can scarcely ever fail to happen in the great guts, from the putrid 

 faeces they contain, which are always observed to be tinged of a black colour 

 from the metallic basis of the salt, part of which, as it has little or no astrin- 

 gency, may doubtless enter the blood, as Signor Menghini observed of the 

 crocus, which is the same substance ; and we know, from the experiments of 

 Lister and Musgrave, that particles, much grosser than those of the white chyle, 

 provided they be not astringent, or very acrid, are conveyed by the lacteals. 

 But the metallic basis being separated from its acid, and thus reduced to a mere 

 calx or earth, can scarcely be supposed to have any medicinal quality whatever, 

 or at least to have any share in the virtues justly attributed to salt of steel. 



As this salt is not only astringent, and consequently a strengthener, but at 

 the same time acts with a gentle stimulus, all its virtues (which are known to be 

 very great in diseases, where the fluids are either viscid, cold, and phlegmatic, 

 or dissolved and watery, from a laxity of the solids) may be accounted for from 

 its immediate effects on the stomach and primae viae, and on the system of the 

 solids in general by consent ; which it would be needless to illustrate by similar 

 examples, because well known to every one the least versed in medical studies. 

 Dr. W., from the obvious qualities of this medicine, and from what had been 

 observed above, deduces the following corollaries : 1 . That salt of steel has no 

 deobstruent or aperient virtue by any immediate action that it can possibly have 

 on the blood, or other animal fluids, as some have imagined ; but that on the 

 contrary it owes this quality to its not entering the blood, which it would other- 

 wise coagulate, and to its action on the solids alone. 2. That in diseases pro- 

 ceeding from a laxity of the solids, great care ought to be taken to restore and 

 invigorate the primae viae; since a medicine (and this we may presume not the 

 only one) whose immediate action is confined to those parts, is yet found by ex- 

 perience to produce so salutary effects in such diseases. 3. That as this salt 

 does not enter the blood, and consequently cannot be in danger of too much 



