Crystallization of Snow. 337 
bottom and sides of the glass, which, when rubbed between 
the fingers, produced a fine ash-coloured powder without 
taste or smell; the whole of which might have been inclu- 
ded in a lady’ ‘ thimble. 
The place where the substance was first found was exam- 
ined, and nothing was to be seen but a thin membranous 
substance adhering to the ground similar to that found on 
the glass. 
This singular niberanes was submitted to the action of 
acids. With the muriatic and nitric acids, both concen- 
trated and diluted, no chemical action was observed, and 
the matter remained unchanged. With the concentrated 
sulphuric acid a violent effervescence ensued, a gaseous 
body was evolved, and nearly the whole substance dissolv- 
ed. There being no chemical apparatus at hand, the 
evolving gas was not preserved, or its properties examined. 
Arr. XX. On the crystallization of Snow, by Professor 
Jacos Green, of Nassau Hall, Princeton. 
Tue crystallization of snow has for a long time excited 
the attention of the curious; few accurate observations 
however have been made upon it. Like the other phenom- 
ena of crystallization, this process is involved in much ob- 
seurity. Beccaria supposed that the regularity often no- 
ticed in these crystals was owing to electricity, and this will 
probably be found the true cause, not only in regard to 
snow but in every other instance of crystallization. We 
know that certain changes in the forms of substances are al- 
ways connected with electrical effects, as for instance when 
vapour is formed or condensed, the bodies in contact with the 
vapours become electrical. Haty has rendered it extreme- 
ly probable that the integrant particles of matter always 
combine in the same body in the same manner, and that the 
combination is occasioned by cohesive attraction. May . 
we not rationally suppose that what is called electrical po- 
larity would induce them to cohere, not promiscuously, but 
dn certain determinate forms. I need not here repeat the 
experiments which prove that the phenomena of electrical 
polarity are precisely analogous to those of magnetism, or 
that magnets will produce asteroidal figures with steel filings. 
With these hints f leave the theoretical part of the subject. 
