d04 PHILOSOPHICAL TBANSACTIONS. [anNO 1789. 



its usual state it may be said to be phlogisticated as well as these. It was evident 

 that the water in the worm-tub was much more heated by the distillation of the 

 spirit of salt than by that of the oil of vitriol, and especially that of the spirit 

 of nitre; so that much of the heat by which it had been raised in vapour must, 

 in the latter case, have been latent in the air that was formed; whereas, in the 

 other case, it was communidated to the water in the worm-tub. 



The vapour of dephlogisticated marine acid, which M. Berthollet discovered, 

 and with which water may be impregnated as with fixed air, being made to pass 

 through the hot earthen tube, became dephlogisticated air, as in the following 

 experiment. Having poured a quantity of spirit of salt on some manganese in 

 a glass retort, he heated it as in the preceding experiments with a proper appa- 

 ratus both for receiving the distilled liquor, and the air. He found -J^ of the 

 air was fixed air, and the remainder very pure dephlogisticated. The liquor re- 

 ceived in this distillation resembled strong spirit of salt in which manganese had 

 been put. This process immediately succeeding that in which the glass tube, 

 joining the earthen tube and worm-tub, was left full of black matter by the dis- 

 tillation of the alkaline liquor, mentioned hereafter, the blackness presently 

 vanished, and the tube became transparent as before. 



Distilled vinegar, submitted to this process, yielded air -§- of which was fixed air, 

 and the rest inflammable: expending 2oz. IQdw. Ogr. of the acid, he got 1 oz. 

 19 dw. gr. of a liquor which had a more pungent smell than it had before dis- 

 tillation. It had also some black matter in it, and some of the same remained 

 at the bottom of the retort when the liquor was evaporated to dryness. The air 

 received was 90 oz. measures. 



Alkaline air is converted into inflammable air in this process, as well as by the 

 electric spark, but by no means in so great a degree. Dr. P. put 2 oz. lOdwt. 

 of water pretty strongly impregnated with alkaline air into the retort, and heat- 

 ing it, sent the vapour through the hot tube ; when he collected 2 oz. 3 dwt. of 

 liquor, which had a disagreeable empyreumatic smell, as well as that of a vola- 

 tile alkali, and it was quite opaque with a black matter, which subsided to the 

 bottom of the vessel. Also the tube through which the air and vapour had been 

 conveyed was left quite black, as mentioned above. 



Dr. P. now recites a few experiments of a diflferent kind from those above- 

 mentioned, and more immediately relating to the doctrine of phlogiston. It is 

 said, by those who do not admit the doctrine of phlogiston, that the metals are 

 simple substances, which, having a strong aflinity to dephlogisticated air, imbibe 

 it when they become calces, without parting with any thing. But that some- 

 thing is really parted with in the calcination, as they will call it, of iron in de- 

 phlogisticated air, appears to be very evident, as well as in the process with steam. 

 In 6-i- oz. measures of dephlogisticated air he melted turnings of malleable iron 



