ON THE OIL OF MONARDA. 
27 
water, and exhibits the remarkable property of retaining its 
fluid state for a very long time; but congeals, on being touched 
with a hard body, immediately at the point of contact, and 
extending rapidly over the entire surface of the oil. The 
greater portion forms large regular crystalline plates, but a few 
drops change into small spherical tufts. The crystals or 
spheres thus produced are distinguished by their opacity and 
their decomposed appearance from those obtained by the dis- 
tillation of the stearoptene alone. To render them transparent 
and lustrous, it is only requisite to melt them and allow them 
to solidify; but if melted frequently, the stearoptene passes into 
the non-crystalline state, without its being possible to state 
more precisely what conditions give rise to this peculiar beha- 
viour. When the fluid stearoptene is touched with a hard 
body, the formation of crystals begins again, and the crystals 
are for the most part opaque; but in general it must have re- 
mained for some time in its fluid state before it can be thus 
brought to solidify. The stearoptene melts at 119°, and soli- 
difies at 101°; when heated to 158°, it solidifies at 93°, when 
the thermometer rises again to 101°; heated to 221°, it con- 
geals at 92°, upon which the thermometer ascends to 99°; 
heated at 284°, it solidifies at 88°, and the thermometer sub- 
sequently ascends to 96°; lastly, when heated to 338°, it soli- 
difies at 81°, and the thermometer ascends to 95°. Its boiling 
point is 428°. 
These numbers show that the point of solidification descends 
as the heating point rises, and that the liberated heat amounts 
up to 275° only to 7°, but at 33S° it is already 14°. At this 
temperature, when more caloric is set free, its tension is greater 
and its escape easier, which facilitates crystallization; to which 
is likewise owing the circumstance, that the stearoptene, when 
distilled alone- and consequently heated to 228°, cannot persist 
in the fluid modification; on the contrary, when distilled with 
water, all the conditions requisite to its production are given. 
The stearoptene is very easily soluble in aether, and espe- 
cially in alcohol, and separates in crystals from both solutions 
