[ 133 3 



long enough to keep a good part of 

 it above the furface cf the water in 

 the time the brim of it is Hiding 

 under water over the fkin. In this 

 way one may fee an immenfe num- 

 ber of very minute bubbles rife 

 continually to the top of the water 

 in the inverted glafs, and gather 

 in larger bubbles at the top. By 

 this method I collected, in a little 

 time, from my arms, a mealure of 

 this air, which feemed to be partly 

 fixed air, as it was fomewhat ab- 

 forbed by the water ; at lead, I 

 thought to find the mafs of it al- 

 ways lefs than it was before. This 

 air put to the nitrous teft was found 

 far from being good refpirable air ; 

 for one meafure of it, with one of 

 nitrous air occupied, 1.46. 



I took a quantity of air in 



like manner from the arms of a 



K 3 healthy 



