of some Calamines. 
The fibrous form of the flowers of zinc, is owing to a crystalli- 
zation of the calx while in mechanical suspension in the air, like 
that which takes place with camphor, when, after having been 
some time inflamed, it is blown out. 
A moment’s reflection must evince, how injudicious is the 
common opinion, of crystallization requiring a state of solution 
in the matter ; since it must be evident, that while solution sub- 
sists, as long as a quantity of fluid admitting of it is present, no 
crystallization can take place. The only requisite for this opera- 
tion, is a freedom of motion in the masses which tend to unite, 
which allows them to yield to the impulse which propels them 
together, and to obey that sort of polarity which occasions 
them to present to each other the parts adapted to mutual union. 
No state so completely affords these conditions as that of me- 
chanical suspension in a fluid whose density is so great, rela- 
tively to their size, as to oppose such resistance to their descent 
in it as to occasion their mutual attraction to become a power 
superior to their force of gravitation. It is in these circumstances 
that the atoms of matters find themselves, when, on the sepa- 
ration from them of the portion of fluid by which they were 
dissolved, they are abandoned in a disengaged state in the bosom 
of a solution ; and hence it is in saturated solutions sustaining 
evaporation, or equivalent cooling, and free from any perturbing 
motion, that regular crystallization is usually effected. 
But those who are familiar with chemical operations, know 
the sort of agglutination which happens between the particles 
of subsided very fine precipitates; occasioning them, on a second 
diffusion through the fluid, to settle again much more quickly 
than before, and which is certainly a crystallization, but under 
circumstances very unfavourable to its perfect performance. 
Ea 
