[ 2 57 ] 
XV. Eafy Methods of meafuring the 'Diminution of Bulk, 
taking place upon the Mixture of common Air and ni- 
trous Air\ together with Experiments on Platina. By 
John Ingenhoufz, M. D. F. R. S. Phyfician to their Im- 
perial Majefties at Vienna. In a Letter to Sir John 
Pringle, Bart. P.R. S. 
TO SIR JOHN PRINGLE, BART. P. R. s. 
SIR, Vienna, 
Nov - 3, i 7 75‘ 
' ifgk’ C OME time a g° I amufed myfelf with fome 
^ experiments relating to nitrous air. Having- 
received from the learned Abbe fontana a copy of a 
pamphlet, which he publifhed this year under the title 
Defcrizione e ufi di alcuni Jiromenti per mifurare la 
falubrita del aria , di Felice fontana. In Firenze , Panno 
m d c c l xxv : per Gaetano Cambiagi Stampatore granducale 
which moft probably will already be known to you ; I 
imitated fome of them, and found them very ufeful for 
the intended purpofe of meafuring the quantity of air 
abl'orbed or diminifhed by mixing the nitrous with the 
common air; by which criterion the degree of the falu- 
bnty of common air may be afcertained according to the 
difcovery of Dr. priestley. Abbe fontana firit pro- 
duces nitrous air in a feparate veffel, and then forces it 
into the glafs, or other veffel, in which it is to remain, till 
a communication be opened between this veffel and the 
Vol. LX VI. L 1 other' 
