VOL. XV.] PHILOSOPHICAL TRANSACTIONS. , 133 



that when the gold is precipitated by this alkali, so called, the urinosum may 

 be so suppressed as not to make an explosion; now in case the precipitate 

 should be dried, and imbibed sometimes with a spirit of urine, it will then re- 

 cover its fulminating power again. So that we see, where heat and flame is, 

 there must be two contrary principles. 



In the next place, if a person take a good spirit of nitre, and drop upon it 

 guttatim, spirit of wine, till it ceases to make an ebullition, the urinosum is 

 then in a balance with the acidum. Only put this salt in a heated crucible, and 

 it will go off with an explosion, only you have here no report, but heat and 

 light; but if you join it with an earth, as aurum fulminans is, you shall then 

 have a report. This spirit of nitre and calcined coral will do, if they are inspis- 

 sated, or brought to be dry. If necessary, he could instance in that burning 

 mixture ex oleo vitrioli, spiritu urinae, et jove ; in all these we have a calidum 

 and frigiduin, which is brought into motion by warmth, and may give heat, 

 thunder, and lightning, as you please to manage it. Salt of tartar, sulphur, 

 and nitre, make a fulminating powder ; he will err here, that will ascribe the 

 effect to sulphur, as if it produced it by virtue of its oil ; it is very plain that it 

 proceeds from the two contrary salts. The acidum alone produces heat, but 

 no flame unless the frigidum be added ; just as a red hot iron may burn or 

 scorch a thing, that it cannot bring to flame, unless the frigidum should meet 

 it. Oil of vitriol burns wood, which it could not do, unless it met its con- 

 trary there. He will pass by the terrible heat excited in the solution of Jupiter 

 and Mars, although many such might be appealed to, which are well known to the 

 experienced. He only mentions the wood-coal; take it, and let it be thoroughly 

 kindled, and then go out of itself: kindle it thoroughly once more, and let it 

 quench or go out in a crucible, or some place where the cold air may not too much 

 annoy it: this may be done 10 or 20 times successively, and it will continue to 

 give heat and light : if this came from oil, sure it must needs be a very fixed oil, 

 and it is impossible it should perform such a work : but a sal duplicatum, which 

 by virtue of its terrestreity is called an alkali, is to be found here. 



A remarkable Case of Hydrophobia. By Dr. Roger Howman, Physician in 



Norwich. N° 169, p. 916. 



Oct. 1, I was called to a patient in this city, who about 6 weeks before had 

 been bitten by a mad fox, on the right hand ; he began to be indisposed the 

 Saturday before with shifting pains, which still increased, especially on his right 

 hand, arm, shoulder and back, but not to confinement. He had been advised 

 to take a dose of the common purging spirit of scurvy-grass, which gave him 



