relating to Air and Water. ^503 



and had loft 3 10 grains of their weight. As the air ceafed to 

 come a coniiderable time before all the water had been tranf- 

 mitted through the tube containing them, I concluded that the 

 air was formed from the phlogifton contained in the bones, and 

 fo much water as was necefiary to give it the form of air. 



This air differs confiderably from any other kind of inflam- 

 mable air,, being in feveral refpecls a medium between that 

 from charcoal. and that from iron. It contains about one- fourth 

 of its bulk of uncombined fixed air, but not quite one-tenth 

 intimately combined with the remainder. The water that 

 came over was blue, and pretty fti'ongly alkaline, which muft 

 have been occafioned by the volatile alkali not having been in- 

 tirely expelled from the bones in the former procefs, and its 

 having in part diflblved the copper of the tube in which the 

 experiment was made. 



I fubjeded to the fame procefs a variety of fubflances that 

 are faid not to contain phlogifion, but I was never able to pro- 

 cure inflammable air by means, of them ; which ftrengthens 

 the hypothefls of the principal element in the conftitution of 

 this hir having been derived from the fubftance fuppofed to con- 

 tain phlogifton, and therefore that phlogifl:on is a real fub- 

 fiance, capable of aflTuming the form of air by means of water 

 and heat. 



The experiments above-mentioned relating to iron were made 

 with that kind which is malleable ; but 1 had the fame refult 

 when I made ufe of fmall nails of cajj, iron^ except that thefe 

 were firmly faftened together after the experiment, the furfaces 

 of them being cryflallized, and the cryfl'als mixing with each 

 other, fo that it was with great difficulty that they could be 

 got out of the tube after the experiment, and in general the 

 Iblid parts of the nails were broken before they were feparated 



from- 



