68 OXYGEN AND HYDROGEN GASES. 



length of this tube was filled with small fragments 

 of fused muriate of lime, except the two extremi- 

 ties, which were stuffed full of amianthus, in 

 order to keep the muriate of lime in its place. 

 This flask was nearly filled with a mixture of sul- 

 phuric acid and distilled water, in the proportion 

 of about four parts of the latter to one part of 

 the former. It was accurately weighed by means 

 of an excellent balance, and the weight of the 

 tube with the muriate of lime, was also separately 

 determined. I then introduced into the flask, as 

 rapidly as possible, a known weight of distilled 

 zinc, in fragments ; the tube with the muriate of 

 lime was fixed in its mouth ; and it was immedi- 

 ately plunged up to the neck in a large trough of 

 water of the temperature of 48, and left in that 

 situation till the zinc was all dissolved. The 

 flask was then wiped dry, put again in the bal- 

 ance, and the loss of weight which it had sus- 

 tained was ascertained ; at the same time, the 

 augmentation of weight of the tube with the 

 muriate of lime was determined. 



The object of this experiment was to ascertain 

 the weight of a given volume of hydrogen gas ; 

 for the experiments related in the last section 

 give us the volume of hydrogen gas evolved dur- 

 ing the solution of a given weight of zinc. It 

 was attended with so many unforeseen difficul- 

 ties, that I was obliged to repeat it ten times be- 

 fore I became aware of all the precautions 



