On a singular instance of Crystallization. 129 
the pyramid ; often grouped, crossing each other at various angles, 
and then exhibiting both terminations ; white, transparent, possessing 
a vitreous lustre, brittle, the fracture disclosing a regular internal ar- 
rangement ; the odor, like that of the oil at the same temperature, 
was slightly fragrant. When detached from the sides of the vessel, 
they instantly subsided in the water. The temperature of the air 
being about 62° Fah., the crystals partially exposed above the water, 
were slowly diminishing in size and resuming a solid form, on those 
below, which were at 45° Fah. ; the difference of temperature be- 
ing maintained by the evaporation of the oil from the surface of the 
fluid, contained in an imperfectly conducting vessel. When with- - 
drawn from the water, and wiped, they soon melted into a colorless 
fluid ; in size, they varied from one and a half inches in length, by 
half an inch in width, to one-tenth these dimensions. 2 
Having often observed the oil of sassafras, inclosed in glass phials, 
perfectly fluid, at all the intermediate degrees of temperature from 
—10° to +70° Fah., it seemed to me probable that a crystallizable 
tompound had been produced by some alteration in the constituents 
‘the oil. With this supposition in view, I carefully removed the ad- 
hering water from some fine crystals, by means of bibulous paper, 
and allowed them to melt in a clean, covered vessel. Portions of 
the resulting fluid, in suitable vessels, were cooled to different ther- 
Mometric points, under circumstances deemed favorable to ordinary 
crystallization ; the oil remained fluid, although its mobility dimin- 
ned by reducing the temperature; yet no tendency to assume a 
solid form was indicated. 
On examination, the fluid obtained from the crystals presented the 
physical and chemical properties of pure oil of sassafras, so far as | 
“tow them ; precautions were taken to remove water if mixed with 
It, but the desiccating compounds were not moistened, nor could it 
be resolved into two fluids by distillation. 
Recurring to the circumstances under which the crystals were first 
observed, a portion of the oil was placed, with three parts of water, 
8 cylindrical glass vessel, the vessel, immersed in a freezing mix- 
©, Was occasionally agitated, until the whole was reduced to a soft 
Solid mass 3 crystals of the oil were now observed, and by allowing 
the vessel to remain in a warm room, the congealed water became 
fluid, leaving the crystals incrusting the sides and bottom of the ves- 
‘el. The crystals thus obtained, presented varieties of the same 
form ag the original crystals from which they were derived, and in 
No. 1. 7 
2 > eae 
