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on naphthaline. 
It is particularly characterized by its odour, which is 
faintly aromatic, and not unlike that of the narcissus and 
some other fragrant flowers. This odour is readily diffused 
through the surrounding atmosphere to the distance of se- 
veral feet, and obstinately adheres for a long time to any 
substance to which it has been communicated. 
When in its purest state, and reduced to powder, it is 
exceedingly smooth and slightly unctuous to the touch ; is 
perfectly white, and of a silvery lustre. 
Sp. gr. rather greater than that of water. 
It does not very readily evaporate at the common atmo- 
spherical temperature : for, a comparison being made be- 
tween this substance and camphor, in the quantity of half a 
grain of each in a very minute state of division, it was found 
that the camphor had entirely disappeared at the end of 18 
hours, while the substance in question had not disappeared 
entirely at the end of 4 days. 
A quantity of it being exposed to heat, in a glass vessel, 
soon melted ; but did not begin to boil till the temperature 
had reached 410° of Fahrenheit : the heat being then with- 
drawn, it remained liquid till cooled down to 180 ; at which 
point the lowest portion was seen suddenly to congeal : the 
remaining portion congealed gradually ; and when the whole 
had become solid, its temperature was 170°. The structure 
of the congealed mass was distinctly crystalline, and the 
crystalline laminae were slightly flexible. 
It is not very readily inflamed ; but when inflamed it burns 
rapidly, and emits an unusually copious and dense smoke, 
which soon breaks into distinct particles that fall down in 
every direction. 
