Formal ion of Volatile Alkali. 381 
in which the quantity of volatile alkali produced is very re- 
markable. In this experiment a few ounces of powdered tin 
are moiftened with fome moderately ftrong nitrous ac^d, and 
after they have flood together a minute or two, about half an 
ounce of fixed alkali is mixed with them. A very pungent 
Imell of volatile alkali is immediately perceived. The experi- 
ment fucceeds equally, if lime be ufed in (lead of fixed alkali. 
Any perfon, who moiftens a drachm or two of filings of zinc 
with a folution of cupreous nitre, and, after they begin to a£t. 
on each other, adds to them a little fait of tartar, will find 
volatile alkali to be produced. Nitrous acid, or cupreous nitre, 
mixed with iron filings, fulphur, and a little water, and kept 
in a clofe veflel for fome hours, yields a fmell of volatile 
alkali ; and if a piece of paper, ftained with a vegetable blue 
fubftance, be thrown into the veflel, it will, in a fhort time, be 
turned to a green colour. In each of thefe experiments the ni- 
trous acid and the water are decompofed. Dephlogifticated air 
from each of them combines with the metal, and their other con- 
ftituent parts, the phlogifticated air of the acid, and inflam- 
mable air of the water, being dilengaged at the fame inftant, 
unite and form volatile alkali. Many other fimilar experi- 
ments might be mentioned; but thefe are abundantly fuffi- 
cient to prove, that if phlogifticated and light inflammable air 
be prefented to each other at the inftant of their feparation from 
folid or liquid fubftances, and before their particles have re- 
ceded from each other, they readily combine and generate vola- 
tile alkali. 
That thefe two fubftances do not combine in their elaftic 
ftate, feems to be owing principally to the inflammable 
air. When thefe two airs combine, it feems neceflary that 
they part with a certain quantity of that fire to which they 
owe their elafticity ; and that, unlefs their attraction to each 
E e e 2 other 
