10 Observations on Naphthaline. 
holds ammonia in solution. When poured out on a flat surface, 
it catches fire almost immediately on the application of flame, 
and burns for a time exactly in the same manner as a thin stra- 
tum of alcohol, the flame being blue and lambent, and without 
smoke; but after a few seconds the flame becomes white, and 
the liquid begins to burn with much black smoke, and with a 
erackling noise. 
A pint of this dark coloured liquid was submitted to very slow 
distillation in a lage glass restort connected with a large glass 
receiver, from the interior of which all communication with the 
external air was excluded by means of a common safety valve. 
The heat was supplied from the flame of an Argand gas burner, 
and was so slight as scarcely to inconvenience the naked hand, 
when held over it immediately under the bottom of the retort. 
The same degree of heat was applied constantly during forty 
hours ; at the end of which time there had distilled into the re- 
ceiver rather more than half a pint of a liquid, which consisted 
of two perfectly distinct portions, which, however, had uniformly 
passed over together from the very commencement of the distil- 
lation. 
The uppermost of these portions, in appearance, resembled. 
pale olive oil, and amoanted to not quite a quarter of a pint. 
The lowermost portion resembied water, but was not perfectly’ 
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transparent, and amounted to rather more than a quarter of a 
pint; but there is ground for believing, from the results of sub- 
sequent distillations, that the proportion of the aqueous product 
is variable ; and that it is greater when the distillation is earried 
on slowly, than when it is carried on rapidly. 
After the above-mentioned products had passed over, a con- 
crete substance as white as snow began to collect in dispersed 
crystalline floceuli, in the upper part of the body and neck of the 
retort, so as in a short time almost wholly to obstruct the pas- 
sage; the oily uid and the water continuing to pass over at the 
same time, but much more slowly than before. 
At the end of sixty hours the original quantity of the dark co- 
Joured liquid was reduced to about a quarter of a pint ; and what 
remained was much thickened in consistence: the heat was 
therefore increased ; and now there began to pass over a darker 
coloured and thicker oil, which, as it advanced further from the 
source of heat, congealed into a substance of the consistence of 
butter, The heat being still more increased, this oil became 
darker coloured and more dense; and when at the last there 
remained in the retort not above one-eighth of the quantity ori- 
ginally poured into it, and the heat of the gas burner had been 
jucreased to the utmost, there arose a heavy yellow vapour, which 
was condensed in the neck of the retort in the form of a farina 
of a bright yellow colour, 
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