a new Eudiometer . 1 23 
mixing the airs is really better than his, or whether the appa- 
rent greater exadlnefs proceeds only from the fuperiority of 
weighing above meafuring : for this reafon I made fome expe- 
riments in which common and nitrous air were mixed in his 
manner, except that I ufed only one meafure of each, as Dr. 
ingen-housz did, and that "he nitrous air was put up firft, 
the true diminution being determined by weight, by firft weigh- 
ing the tube under water with the nitrous air in it, and 
then adding the common air, and weighing the tube again 
under water. It was unneceeflary, for the reafons given in 
p. 1 10. and 1 1 2. to determine the quantity of either the ni- 
trous or common air by weight. My reafon for this variation 
was, that it afforded a much eafier method of determining the 
quantities by weight, was lefs trouble, and, I believe, muff be 
at lead: as exaft : for I have always found, that the experiments 
made with the Abbe fontana’s apparatus, in which I ufed 
only one meafure of each air, agreed better together than thofe 
in which I ufed two of common, and added the nitrous air by 
one at a time ; and 1 imagine it can be of no fignification whe- 
ther the nitrous or common air is put in firif, as I cannot per- 
ceive the diminution to be fenfibly greater in one of thofe ways 
than the other *. 
* It is not extraordinary, that in this method the diminution is juft the fame 
whether the common or nitrous air is put up firft, notwithftanding that in mine 
it is very different ; fince in this method the two airs mix in the fame manner 
whichever is put up firft: whereas in mine, the manner in which they mix 
is very different in thofe two cafes ; as in one, fmall portions of common air 
come in contact with large portions of the nitrous ; and in the other, fmall por- 
tions of nitrous air come in contaft with large portions of common air. 
Iy 2 
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