and Naphthaline, and on a new Acid produced. 327 
Some of the results obtained by the use of the oil gas pro- 
ducts are very peculiar. If, when completed, I find them suf- 
ficiefitly interesting, I shall think it my duty to place them 
before the Royal Society, as explicatory of that action_of sul- 
phuric acid which was briefly noticed in my last paper. 
Most authors who have had occasion to describe naphthaline, 
have noticed its habitudes with sulphuric acid. Mr. Brande, 
several years since* stated that naphthaline dissolved in heated 
sulphuric acid “ in considerable abundance, forming a deep 
violet coloured solution, which bears diluting with water with- 
out decomposition. The alkalies produce in this solution a 
white flaky precipitate, and if diluted the mixture becomes 
curiously opalescent, in consequence of the separation of nu- 
merous small flakes.” The precipitate by alkali was probably 
one of the salts to be hereafter described. 
Dr. Kidd observes +, that ‘it blackens sulphuric acid when 
boiled with it; the addition of water to the mixture having no 
other effect than to dilute the colour, neither does any preci- 
pitation take place upon saturating the acid with ammonia.” 
Mr. Chamberlain states {, that sulphuric acid probably de- 
composes naphthaline, for that it holds but a very small quan- 
tity in solution. The true interpretation of these facts and 
statements will be readily deduced from the following experi- 
mental details. 
1. Production and Properties of the new Acid formed from Sul~ 
phuric Acid and Naphthaline. 
Naphthaline, which had been almost entirely freed from 
naphtha by repeated sublimation and pressure, was pulverized ; 
about one part with three or four parts by weight of cold sul- 
phuric acid were put into a bottle, well shaken, and left for 
36 hours. The mixture then contained a tenacious deep red 
fluid, and a crystalline solid ; it had no odour of sulphurous acid. 
Water being added, all the liquid and part of the solid was 
dissolved; a few fragments of naphthaline were left, but the 
greater part was retained in solution. The diluted fluid being 
filtered was of a light brown tint, transparent, and of an acid 
and bitter taste. 
For the purpose of combining as much naphthaline as pos- 
sible with the sulphuric acid, 700 grains, with 520 grains of 
oil of vitriol were warmed in a Florence flask until entirely 
fluid, and were well shaken for about 30 minutes. The mix- 
ture was red; and the flask being covered up and left to cool, 
* Quarterly Journal of Science, viii. p. 289. 1819. 
+ Philosophical Transactions, 1821, p. 216. 
t Annals of Philosophy, N.S. vi. p. 186. 1823, 
was 
