on the Production of Dephlogjfiicated Air, 
99 
Experiment N° 1 1 . 
The globe N° 6. with human hair, furnifhed flilllefs air than 
that with ravelings of linen in the laid mentioned experiment ; 
but, notwithfdanding the fmallnefs of the quantity, it was con* 
fiderably fuperior in quality to atmofpheric air, for, proved with 
nitrous air, it gave ia -f- 20 zz 3,45, or 155; whereas common 
air, proved at the time, gave ia + ik—i,o8 , or 92. 
Experiment N° 12. 
To afcertain the relative goodnefs of the air furnifhed by the 
water in thefe experiments, and of that produced by expofing 
frefh healthy vegetables in water to the action of the fun’s light, 
according to the method of Dr. Ingen-housz, I collected a 
fmall quantity of air from a Idem of a pea plant, which had 
four healthy leaves upon it, and found it to be much inferior to 
that furnifhed in the experiments with filk, and the various 
other fubftances I made ufe of. Proved with nitrous air, it gave 
in -j- 2n— 1 ,05, or 1 95. 
An intire plant of houfewort, of a moderate fize, expofed 
in 12 ounces of water 7 hours, to the action of the fun’s rays, 
at a time when the weather was remarkably fine, and very hot, 
furnifhed about | of a cubic inch of air, which was fo much 
worfe than common air, that 1 meafure of it, with 1 meafure 
of nitrous air, occupied 1,36 meafures ; or it was = 
1,36, or 64. But I lay no kind of fdrefs upon the refult of 
this experiment, as it is more than probable, that the badnefs of 
the air arofe from the roots of the plants ; for from the leaves 
alone I have frequently fince obtained air, which appeared to 
be confiderably better than common air. 
O 2 
From 
