1 14 Mr. cavendisi-i’s Accdunt of 
In the fir ft method of proceeding I found, that the diminu- 
tion was fcarce fenfibly lefs when I ufed one meafure of nitrous 
air than when I ufed a much greater quantity ; fo that one 
meafure is fufncient to produce the full diminution. I chufe, 
however, to uie i*, for fear the nitrous air may be impure; 
4-ths of a meafure of nitrous air produced about and |ths 
of a meafure about f.tlis of the full diminution. 
I found alfo, that there was no fenfible difference in the 
diminution whether the orifice by which the air palled out of 
the veflel A into the bottle M was only -f T th of an inch in 
diameter, or whether it was .gth of an inch ; that is, whether 
the air efcaped in fmaller or larger bubbles. The diminution 
was rather lefs when the bottle was fhook gently than when 
brifkly ; but the difference between fhaking it very gently and 
as brifkly as I could was not more than . r 4- dth of a meafure. 
But if it was not fhaken at all the diminution was remarkably 
lefs, being at firft only ,9 ; in about 3', indeed, it increafed to 
,93, and after being fhaken for about a minute it increafed to 
,99 ; whereas, when the bottle was fhaken gently, the dimi- 
nution was 1,08 at firft mixing, and did not increafe fenfibly 
after that time. The difference proceeding from the difference 
of time which the air took up in palling into the bottle was 
rather greater; namely, in fome trials, when it took up 80" 
in palling, the diminution was - r 4~o ( fth s greater than when it 
took up only 2 2", and about T -i^dths greater than when it took 
up 45' ; in fome other trials, however, the difference was lefs. 
It appears, therefore, that the difference arifing from the dif- 
ference of time which the air takes up in palling into the bottle 
is confiderable ; but, as with the fame hole in the plate T)d it 
will take up always nearly the fame time, and as it is ealy ad- 
jufting the fize of the hole, fo as to make it take up nearly the 
time 
