38 Sir Benjamin Thompson's Experiments 
housz; and under the circumftances the mod: favourable, it 
was fo good that i meafure of it required 4 meafures of nitrous 
air to faturate it, and 3,65 meafures of the two airs were de- 
ll royed ; or, proved with nitrous air it gave ij + 472 = i ,35, 
which, I believe, is better than any air that has yet been 
produced in the experiments with vegetables. 
The method I have here adopted of ufing algebraic cha- 
racters in noting the refult of the experiments made to deter- 
mine the goodnefs of air, though not ftriclly mathematical, is 
very convenient ; and for that reafon, I fhall continue to make 
ufe of it. a reprefents’the air which is proved ; 71 nitrous air ; 
and the numbers which are joined to thefe letters fhew the 
quantities, or the number of meafures, of the different airs 
made ufe of in the experiment. The other number, which 
Hands alone, or without any letter attached to it, on the other 
fide of the equation, (hows the volume, or the number of 
meafqres and parts of a meafure to which the two airs are 
reduced after they are mixed. I fhall fometimes add a fourth 
number, {hewing the quantity of the two airs deftroyed, as this 
more immediately fliews the goodnefs of the air which is 
Thus, in the experiment laft mentioned, 1 meafure of the 
air proved, mixed with 4 meafures of nitrous air, were reduced 
to 1,35 meafure, consequently 3,65 meafures of the two airs 
were deftroyed ; for it is 1 + 4= 5 - 1,35 = 3,65, and the refult 
of this trial I fhould write thus, i<z + 4«= 1,35, or 3,65. 
Or, for ftill greater convenience in praClice, as this laft num- 
ber 3,65, or 3-rV-s-lhews more immediately the goodnefs of the 
air in queftion, as I have juft: obferved, by fuppofing with Dr. 
Ingen-housz the meafure of the eudiometer to be divided 
into 100 equal parts, it will be 1000 + 400 «= 135, and 365, 
expreffing 
