NOTE ON STELLIFORM CRYSTALS. 5 
have shewn me several curious facts: amongst others, one that has 
led me to the present inquiry. I have found, for example, that com- 
pound stellate crystals, resembling exactly many of the star-crystals 
of snow, may be produced in salts belonging to various systems of 
crystallization—although I have not succeeded in obtaining them 
from Hexagonal salts: another fact—so far as it goes—against the 
assumed crystal system of snow. Omitting all doubtful and in any 
way unsatisfactory cases, I have obtained repeatedly these stelliform 
combinations in the five substances enumerated below; and the list, 
I have no doubt, will be ultimately much extended : 
Monometric Substances. 
Camphor = 20C, 16H, 20. Star-crystals obtained from solution 
in alcohol. These crystals require to be examined as soon as formed, 
as they evaporate with great rapidity. Sal Ammoniac = Am Cl. 
Trimetric Substances. 
Sulphate of Magnesia = MgO, SO* + 7HO. 
Monoclinic Substances. 
Glauber Salt = NaO, SO* + 10 HO. 
Bi-carbonate of Potash = KO, 2CO? + HO. 
Observed star-crystals of Camphor, Sulphate of Magnesia, and 
Glauber Salt are shewn, respectively, in figures 1, 2, and 3.* 
Fig. 2. Fig. 3. 
The production of six-rayed stellate crystals in Glauber Salt and 
Bi-carbonate of Potash, is a fact of some interest: since it has been 
supposed that Monoclinic forms could not oceur in groupings of this 
kind. None it is true are met with amongst minerals of natural 
formation belonging to the Monoclinic System, but my results shew 
clearly that they are capable of occurrence. 
Summary.—From the observations recorded in this communication, 
the following conclusions may be deduced : 
(1.) Stelliform six-rayed crystals are common to various systems— 
Ba aig eg i ee 
* These figures are very badly executed, but they will serve to show the general character 
of the crystallizations to which they refer. 
