574 Scientific Proceedings, Royal Dublin Society. A 
solidification of the melted mass or when it is dissolved in melted e 
silver iodide. It may, however, be remarked that the skeleton 
cr ystals obtained in the way last mentioned are much more a 
massive than those out of aqueous solutions. Difficulty of solution — 
has therefore much. the same effect as viscosity, since it brings ; 
about the formation of more delicate forms.’” 
Lehmann tells us that ‘“‘ bending and branching arise almost — 
simultaneously.” They are of very common occurrence among 
cases where very great irregularity in the rate of growth at different : 
places is produced by one or other of the causes just enumerated. 
Thus, according to the same author, Isohydrobenzoindiacetate 
erystallizes out of alcohol in singular bent crystals resembling 
frequently a rolled up band. This form is, however, retained 
only so long as the crystals are sufficiently thin to show inter- 
ference colours. As they thicken they straighten themselves out 
more and more, and finally hecome fine regular rhombic crystals. 
Besides the bending described, a bending perpendicular to it 
generally takes place. 
Again, if a mixture of chromic chloride with mercuric chloride 
in aqueous solution is placed on an object glass under a cover 
and then evaporated till it becomes fairly thick, very long thin 
capillary crystals are formed as the cooling proceeds, which at first 
are curled up in spirals, but unroll themselves as they grow thicker. 
As a third striking instance, if a solution of wax in naphtha is 
rapidly cooled, radiated aggregations of very thin plates are at 
first formed ; these spherolites do not, however, continue long, but 
give way in the middle, extending themselves to form a ring which — 
then breaks up into several bow-shaped fragments. Hach in- 
dividual of these winds and bends itself as the growth proceeds 
till at length it again falls to pieces. And all this stretching and 
bending and fracturing takes place with such energy that the whole 
crystal mass in effecting these involved movements appears as 
though alive. 
As a final instance cupric chloride mny be mentioned. Com- 
monly this substance crystallizes out of acidified aqueous solution 
; 
ly 
'n 
10, Lehmann “Ueber das Wachstum der Krystalle.’’ Zeitschr. f. Kryst., 1, 
pp. 457-459. 
