Crosse’s Hxperimen the Voltaic Battery. 135 
however the timid may shrink from investigation, the more com- 
pletely the secrets of nature are laid bare, the more effectually 
will the power of that Great Being be ee who seems to 
have ordained, that 
*¢ Order is Heaven’s first law.” 
I beg to remain, in the mean time, my dear Sir, 
ect “very sincerely, 
Ayprew CROSSE. 
Broomfield, Dec. 27, 1837. : 
Pp. s- Since weititittr the ovis account, I hive obtained the in- 
sects on a bare platina wire plunged into fluo-silicic acid, one inch 
below the surface of the fluid at the negative pole of a small bat- 
tery of two inch plates in cells filled with water. This is a some- 
what singular fluid for these insects to breed in, who seem to have 
a flinty taste, although they are by no means coulda to siliceous 
fluids. This fluo-silicic acid was procured from London some 
time since, and consequently made of London water ; so that the 
idea-of ‘their being natives of the Broomfield water is quite set 
aside by this result. The apparatus was arranged as follows: 
Fig. 7, a glass basin (a pint one) partly filled with fluo-silicic acid 
to the level 1. 2, a small porous pan, made of the same materi- 
als as a garden pot, partly filled with the same acid to the level 2, 
with an earthen cover, 3, placed upon it, to keep out the light, 
dust, &c. 4, a platina wire connected with the positive pole of 
the battery, with the other end plunged into the acid in the pan, 
and twisted round a piece of common quartz; on which quartz, 
after many months’ action, are forming singularly beautiful and 
perfectly formed crystals of a transparent substance, not yet ana- 
platina wire passes under the cover of the pan. 5, a platina wire 
connected with the negative pole of the same battery, with the 
other end dipping into the basin, an inch or two below the fluid ; 
and, as well as the other, twisted round a. piece of quartz. By 
this arrangement it is evident that the electric fluid enters the po- 
rous pan by the wire 4, percolates the pan, and passes out by the 
wire 5. It is mow upwards of six or eight months (I cannot at 
this moment put my hand on the memorandum of the date) since 
this apparatus has been in action, and though I have occasionally 
lyzed, as they are still growing. These crystals are of the modi- — 
fication of the cube, and are of twelve or fourteen sides. — ‘The - 
