302 Dr, Priestley's Experiments and Ohfej vations 



ioofe, or only niiited to water ; and perhaps future experi- 

 jtiients may difcovcr the operation of this circumflance. 



There is foaie analogy between the experiment of the calx 

 of iron imbibing inflammable air, and the iron itielf imbibing 

 dephiogidicated air. In the former cafe water is produced, and 

 in the latter Jixed air. However, this cafe of iron imbibing 

 dephlogifticated air more nearly relembles the cafe of the blood 

 in the lungs imbibing tlie fame kind of air, and in both the 

 cafes as dephlogifticated air is imbibed, fixed air is formed. 

 This, therefore, feems to be a confirmation of the conclufioii 

 which I drew from my former experiments on blood, viz. that 

 it parts with phlogifton in re fpi ration. Only I would now 

 add, that at the fame time that it parts with phlogifton it takes 

 in dephlogifticated air, which makes the cafe perfectly fimilar 

 to that of the experiment with iron, which likewife parts with 

 phlogifton to form fixed air, at the fame time that it imbibes 

 dephlogifticated air in conta6l with which it is fufed. 



I propofe to referve for a future communication the conti- 

 nuation of thefe experiments, containing an account of the ap- 

 plication of the fame procefs to other fubftances ; but it may 

 not be amifs juft to mention a few of the general refults, and 

 thofe which have the neareft connexion with the experiments 

 recited above. 



After having tranfmitted fteam in contact with charcoal and I 

 iron in a copper tube, I propofed to do the fame with other fub- ■ 

 ftances containing phlogifton, and J began with bones^ which 

 were burnt black, and had been fubje^led to an intenfe heat, 

 covered with fand, in an earthen retort. From three ounces of 

 bone thus prepared, and treated as I had done the charcoal, I 

 got 840 ounce meafures of air, with the lofs of 288 grains of 

 water. The bones were by this means made perfedly white, 

 3 and 



