116 Scientific Intelligence. 
- DE, which is put in communication with the 
other pole of the pile. When the spring 
C ‘ touches the spring D re the hiopran is 
on. ‘The vibrations produced by this arrange- 
ment are so rapid that it produces iT 
like the buzzing of a fly.* This apparatus has been applied to clectit= 
medical purposes, in which it is a convenient substitute for seine 
wheels. 
Corr espondence of. T. S. Hunt of Montreal, on Atomic Yotestet 
As to atomic volume I have a new suggestion. In the gaseous state, 
volumes and equivalents are identical, and an idea of this kind, as true 
to a certain extent of bodies in the solid form, lies at the basis of the 
calculations of Kopp and yourself ; but while in some cases the volt 
appears identical, in others it varies widely. Now in vapors we shoald, 
from a want of such conformity, have argued that the equivalent was 
rightly fixed, and this you know is readily determined otherwise in 
most organic volatile bodies; while in minerals we have arbitrarily as- 
sumed the simplest ratio of the constituents, as expressing the” “equiva. 
lent, and shaped our atomic volume to this. Now I suppose that all 
bodies i in the same crystalline form have the same atomic volume, and 
hence from this we may calculate their true equivalents ; hence 
relative equivalent being the same, the density is the index of i 
complexity, or in other td Keeper: (pardon the truism,) their de 
gree of condensation. To begin by fixing an equivalent,—Alum (i in the 
regular system,) is 21S aks Oat and with an equivalent of : 
H=1) and sp. gr. 1 5 has a volume of 271. Chrome alum is 2686. 
‘The mean is about 270. Compared with this, magnetite is not ( 
Fe20s) with a volume of 22°7, but 12Fe0, 12Fe203=— = (Fe afeve, O18) 
with volume of 22°7 & 12 2—972: 4,and soon. Rhombohedral and octa- 
hedral specular jron have about the same sp. gr., and if we assume t vholit 
volume to be the same, we have a transition to another system 
change of volume; we have for Corundum, 15°5 pion 
with a volume of 268-5, and homologue of (MasO«s) or el 
So Polybasite, i in which. copper in a double equivalent €u, enters, oh 
have been able to prove,) is accurately represented by 8( Ag, Cu 
(Sb, As)St=MsSb, S12: bat its sp. gr. corresponds to (M16Sb252 
with a volume of 270. Quartz (silica being SiO) is Si2sOz5, at mee 
267. [Mr. Hunt proposes to present his views in detail in our Be 
number,—z. D. p. D.] e 
ct i giles ee oe 
» [This apparatus is very nearly identical e armature bresk- 
piece of Dr. =< Daniel Davi, for an ene 
of an easy adjustment herp os ibang eV y facility * 
gra. C 
PG AEE oe El SSS a kN as an a, oa ai 
ee on 
