ae NOS . 
<A Phenilistiiginsie 117 
a watch glass. The crystallizing pellicle on the surface, exhibited 
curved lines as represented in fig. 1, which lines it is observed are stri- 
kingly similar to those assumed by iron filings sprinkled on a paper 
which is placed over a magnet. 
Wires similarly arranged were dipped into sulphate of iron; eryss| 
tallization-commenced around the north pole, and soon after around 
the south, ‘The position of the crystals showed an obvious: tendency 
to. conform to lines of magnetic direction. i. 
When protronitrate of mercury was exposed to the same action, 
crystallization began at the north pole, and proceeded rapidly to a line 
half way between the two wires, one half of the fluid being crystallized 
and the other remaining fluid. At length a few crystals formed around 
the south pole wire, taking a direction towards those of the north pole. 
Fig: 1. Fig. 2. 
_ Crystallization of nitrate of mercury on a plate of glass over an 
electro-magnet capable of holding fifty pounds, had the arrangement of 
lines in figure 2 annexed: and with a small battery of more permanent 
but less powerful arrangement, the result in figure 3 was obtained. 
When a plate of copper was substituted for the glass, and a weak 
solution of nitrate of silver employed, the curves in figure 4 were 
uced. 
Sid Fig. 5. _ 
— 
A tolerably strong solution of nitrate of silver was put on the copper 
Plate, and this left in contact with the magnet for a night, when the cop- 
per was bitten deeply by the acid of the salt of silver, in the oval form 
in figure 5, the inner part of the oval remaining bright. 
e Figure 6 illustrates another curious result obtained on a glass plate 
from a weak solution of nitrate of silver and an equally weak solution 
of sulphate of iron ; in five minutes the silver was precipitated*in curves 
as in figure 4, and shortly two curious curved spaces were formed by 
