544 PHILOSOPHICAL TRANSACTIONS. [aNNO 1779. 



which is to be immediately inverterl into the orifice of the air pistol, and, after 

 giving it a gentle squeeze, withdrawn out of it: after which, a bullet or a cork 

 is to be thrust into the mouth of the pistol, when it is ready for firing. This 

 whole operation may be performed in the space of 5 or 6 seconds. 



The considerable force of explosion, and the loud report of the ordinary in- 

 flammable airs, induced Mr. Volta, of Como, to believe, that these airs might 

 perhaps become a substitute for gunpowder. K this expectation had been well 

 founded, the greatest desideratum would have been to find out a way to produce 

 such air at any time without trouble, and to carry it about in as little compass as 

 possible : which two conditions I should have pretty nearly fulfilled, as all the 

 inflammable air requisite for the explosion of the pistols contrived by Mr. Volta, 

 is contained in the bulk of one single drop of aether ; which drop, poured in the 

 pistol itself, is fully sufficient to produce a very powerful explosion. But how 

 far this expectation of Mr. Volta, as to the use of inflammable air in oflfensive 

 arms, is well grounded, I shall attempt to explain in the subsequent part of this 

 paper. 



This inflammable air (which perhaps might more ])roperly be called vapour, as 

 it is absorbable by water) has the principal properties of the other inflammable 

 airs, viz. it will not inflame but where it is in contact with common or dephlo- 

 gisticated air ; and tiierefore only takes fire at the top of the vessel containing it, 

 the flame going gradually downwards till the whole is consumed, if the vessel is 

 of a cylindrical form, and pretty-wide. If it is diluted with common air, but 

 not sufficiently, it will burn as other inflammable air without exploding. Being 

 sufficiently diluted with common air, especially with dephlogisticated air, it ex- 

 plodes with a very great report and a considerable force. It is unfit for respira- 

 tion in a concentrated state, and is as mortal for an animal plunged into it as any 

 other of the inflammable airs ; though in a diluted state it seems to be rather 

 pleasant to the organs of respiration. 



It differs in some respects from the common inflammable airs ; as, for in- 

 stance, it is much heavier, as is already observed, than any of the other inflam- 

 mable airs, and even than common air. It does not inflame or explode with so 

 small a spark of electrical fire as the other inflammable airs, requiring the ex- 

 plosion of a Leyden phial to be fired with certainty, though one single inch of 

 coated glass will be suflicient ; so that a Leyden phial, containing 12 or 14 

 square inches of coating, may fire an air pistol loaded with this kind of air 

 several times, if the charge be divided by taking it out with a small glass tube, 

 fitted up in the maimer I described in the paper I had the honour of laying 

 before the r. s. last year; where I describe a kind of an electrical match to light 

 a candle with. Ihis air being in contact with water, is absorbed by it. in a few 

 days, though the water be not stirred: and much sooner loses its inflammability 



