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the valley of Aosta ; and VI. a green substance containing garnets, forming 
a vein in gneiss near Nantes. 
The author remarks upon the similarity of these minerals, both in cha- 
racter and composition, to the true jadeites, which are also generally found, 
not in position, but in the form of pebbles and blocks transported by 
glaciers or by running water. In Thibet there is no doubt that deposits of 
jadeite must exist, and the author infers that it also occurs in America, pro- 
bably in Mexico and in the regions bordering on the Amazons. The 
analyses and observations given by him in his present paper would seem to 
show that the same mineral exists also on the European continent, probably 
in or near the chain of the Alps. If this be the case, there is no need to 
invoke a migration of ancient Asiatic populations to account for the presence 
of jadeite axes on this continent. 
Geniculated Zircons. — Mr. W. E. Hidden describes and figures (Silliman’s 
Journal, Juue 1881) twin crystals of zircon obtained by him from the new 
locality of apatite and sphene at Renfrew, Canada. The twinning plane is 
the same as in cassiterite and nitrite. The twin figured by him weighed 
over 35 grammes, and was remarkably perfect and had well-polished 
planes. Its colour was deep brown-lake, and it was transparent in spots. 
Previously described twins of zircon have been microscopic and ques- 
tionable. 
PHYSICS. 
Electric Storage of Dynamical Energy . — The following article and letters, 
which have appeared in the Times during May and June, mark such an epoch 
in the history of electricity that they deserve reproducing in extenso : — 
1 We publish this morning a letter from Sir William Thomson, supple- 
mentary to that in which u F. I. R. S.,” on the 16th of May, gave the first 
account of the conveyance from Paris to Glasgow of a box containing active 
electricity in a portable form ; and it would certainly appear, from both 
communications, that applications of ever-widening utility are opening up 
before the most potent of natural forces, which seems to be rapidly becom- 
ing also the most manageable. Our readers will remember that “ F.I.R.S.” 
related how he witnessed in Paris, on the 9th of May, the charging of four 
of Faure’s batteries with electricity obtained from an ordinary Grove’s 
battery. The four batteries were enclosed in a wooden box, about a cubic 
foot in measurement, and weighing, with its contents, about 75 lbs. This 
box of “ electric energy ” was handed by M. Faure to our correspondent, 
who brought it with him across the Channel, and, after seventy-two hours 
of travelling, delivered it to Sir William Thomson at Glasgow, in order that 
the power of its charge might be made the subject of observation and expe- 
riment. The box was believed to contain electricity in quantity equivalent 
to a million foot pounds ; and we now hear that this belief has been fully 
borne out by experiment. No appreciable loss was incurred during the tran- 
sit ; and the energy put into the four batteries in Paris remained in them 
until it was applied to working purposes in Glasgow. So completely was 
