Muriatic Acid and Chlorine. 105 
with which I am acquainted. The slightest touch of the finger 
breaks them across. Digested in pure nitric acid somewhat 
dilute, the segments only partially dissolve, bits of muriate of sil- 
ver, of their own shape, being left in the liquid. 
The ignited copper turnings, after experiencing the action of 
sal ammoniac, are found to have lost also their original lustre, 
and have acquired a dull brown colour. Digested in water, a 
liquid muriate is obtained, which gives the characteristic brown 
precipitate with prussiate of potash. 
The most considerable of my experiments with turnings was 
made with the tube of Reaumur’s porcelain, which, as it con- 
tains no oxide of lead, is not liable to any ambiguity on this score, 
and being capable of sustaining a very high heat without fusion, 
permitted me to obtain very satisfactory results indeed. 
Thirty grains of recently heated sal ammoniac being put down 
to the sealed end, 200 grains of bright turnings of very pure soft 
iron were introduced over it, so as to occupy six inches of the 
tube. The glass tube above described, was attached by the 
elastic gum collar. The part holding the iron being brought to 
bright ignition, the sealed end of the tube was advanced by de- 
grees almost imperceptible. As soon as the salt began to ex- 
hale, moisture began to condense in the glass tube, though none. 
ever appeared prior to heating the sal ammoniac. The evolu- 
~ tion of gas was much more copious than in any of the experi- 
ments with the other metals. When allowed to escape through 
the quicksilver into the air, it exhibited the dense cloud,.and had 
the odour, of muriatic acid. Received into a tube over mercury, 
and then exposed to the action of water, +4, parts of the volume 
were absorbed, which on trial were found to be pure muriatic 
acid. The remainder was a mixture of azote and hydrogen, in 
the proportions very nearly that are known to constitute am- 
monia. I analysed this mixed gas, by explosion with half its 
volume of pure oxygen, in a peculiar apparatus which I shall 
describe in the sequel. On firing 100 measures with the electric 
spark, 76°2 disappeared, two-thirds of which, ==50°8, are hy- 
drogen. Before explosion, the haparert volumes consisted of 
66% ammoniacal gaseous matter, +354 oxygen. Of these 66% 
parts, 50°S are hydrogen, and 195° 86 azote; or, in the 100, 
76:2 + 23°8. But, by Gay-Lussac, one volume. of azote unites 
with three volumes of hydrogen to form ammonia. Hence 23:8 
measures of azote should have been accompanied with only 71*4 
of hydrogen, instead of 76*2 actually obtained. This excess of 
hydrogen is due to the decomposition of a little of the watery 
product, in the formation of the muriate of iron. ‘That muriate 
of ironis formed, is proved by many circumstances. First, the 
disappearance of the acid in the gaseous products, Sal. am- 
moniac 
