4 PHILOSOPHICAL TRANSACTIONS, [aNNO 1744. 



, whereas the volatile spirit of sulphur long preserves its volatility, the purer gas 

 being here lodged in a pure acid liquor, less dense and gross than oil of vitriol ; so 

 that when, by being long unstopped, this acid spirit loses of its volatility, as it 

 will do, yet it never loses of its acidity; and even then appears to be the most 

 pure and perfect mineral acid we can any ways procure. And as to the gas sul- 

 phuris, when made in perfection; this is no more than the fumes of burning brim- 

 stone caught and detained in water: so that this preparation, wanting the acid, 

 cannot be compared in that respect with this spirit, which has it in perfection. 



10. What the medicinal virtues and uses of this volatile acid of sulphur may be, 

 Mr. S. submits to the Society, and the learned physicians, to whom it belongs; 

 he only begs leave to observe, that if what is found in numerous learned physic- 

 books be just, there are hopes that it may prove a noble medicine in many kinds 

 of fevers, the small-pox, and even in plagues. In some of these books it is siad, 

 that malignant fevers are owing to a superabundance of volatile alkaline salts in 

 the body ; and if that be the case, one might hope to neutralize or destroy such 

 a superabundancy of volatile alkaline salts, by the prudent use of this fine vola- 

 tile acid; which is capable of being mixed with water, juleps, and most sorts of 

 drinks. 



1 1 . Mr. S. likewise finds, that the origin of all pestilences and plagues has 

 been assigned to the following causes, viz. ( 1 .) The carcases of men, horses, or 

 cattle, killed or slain, and putrefying above ground by heat and moisture, and 

 thus infecting the air by their noxious, volatile, urinous alkaline salts, that copi- 

 ously issue from them in such a putrefying state. (2.) Dead fish, thrown out of 

 the sea, and putrefying on the shore ; or swarms of dead insects, bred in fens and 

 marshes, drowned in the ocean, and thrown on shore by the tides, and left to 

 putrefy in hot moist climates. (3.) Woollen goods, silks, and apparel, packed 

 up or worn by infected persons, or those that attended the sick, or that came 

 from infected places. (4.) Unwholesome diet, or cormpted putrefying meats, 

 abounding with too subtilized, or too rarefied, volatile, urinous salts. (5.) Mi- 

 neral, arsenical, and poisonous damps, vapours, exhalations, &c. arising from 

 volcanos, mines, grottos, by means of subterraneous heats and fermentations. 



12. It were easy, by natural reasoning on these causes assigned of the plague, to 

 show that this distemper consists in a kind of putrefactive state of the body, when 

 the salts are volatilized, unsheathed, and let loose to tear and wound the solids, 

 after destroying the texture; and consequently that the volatile acid, here shown 

 to be easily procurable, is a natural remedy in such cases.* 



* These speculations of Mr. Seehl's concerning the antipestilential properties of acids, have been 

 verified, to a certain extent, by recent experiments. But from these experiments, it appears, that the 

 said acids prove better suited to such purposes in proportion as they are more oxygenized. Henea 

 the sulphuric acid is more antipestilential than the sulphurous acid, or this author's volatile acid of 

 sulphur. 



