[ *n ] 



fiammability may, in fome meafure, arife from the 

 air continuing fo much longer in the bladder when 

 it is made very flowly ; though I think the difference 

 is too great for this caufe to have produced the whole 

 of it. It may, perhaps, deferve to be tried by a 

 different procefs, without a bladder. 



Inflammable air is not thought to be mifcible 

 with water, and when kept many months, feems, in 

 general, to be as inflammable as ever. Indeed, 

 when it is extracted from vegetable or animal fub- 

 ftances, a part of it will be imbibed by the water in 

 which it ftands $ but it may be prefumed, that in this 

 cafe, there was a mixture of fixed air extracted from 

 the fubihnce along with it. I have indifputable 

 evidence, however, that inflammable air, ftanding 

 long in water, has actually lofl all its inflammability, 

 and even come to extinguish flame much more than 

 that air in which candies have burned out. After 

 this change it appears to be greatly diminished in 

 quantity, and it ftili continues to kill animals the 

 moment they are put into it. 



This very remarkable fact: firft occurred to my ob- 

 fervation on the twenty- fifth of May 1 77I3 when I 

 was examining a quantity of inflammable air, which 

 had been made from zinc, near three years before. 

 Upon this, I immediately let by a common quart 

 bottle filled with inflammable air from iron, and 

 another equal quantity from zinc 3 and examining 

 them in the beginning of December following, that 

 from the iron was reduced near one half in quantity, 

 if I be not greatly miiiaken; for I found the bottle 

 half full of water, and I am pretty clear that it was 

 full of air when it was fet by. That which had 



been 



