^02 Dr. Priestley's ExperimcJits and Obfeivatlons 



looi'e, or only united to water ; aiid perhaps future experi- 

 ments may difcover the operation of this circumftance. 



There is fome analogy between the experinr-ent of the calx 

 of iron imbibing inflammable air, and the iron itfelf imbibing 

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

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

 dephlogiflicated air more nearly refembles the cafe of the blood 

 in the lungs imbibing the 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 conclufion 

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

 it parts with phlogifton in refpi ration. Only 1 would now 

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

 in dephloglfticated air, which makes the cafe perfe6tly 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 contact with which it is fufed. 



I propole 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 

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

 ftances containing phlogifton, and I began with bones, which 

 were burnt black, and had been fubjected 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 8-|0 ounce meaiures of air, with the lofs of 288 grains of 

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

 3 and 



