390 Miscellanies. 
rent, or that from the*tendon to the surface of the muscle, as the most 
simple case of the muscular current. The tendinous fibres are continued 
among the muscular fibres, whilst the sarcolema merely envelopes the said 
muscular fibres. This result is rendered still more probable when we 
call to mind that the same laws preside over the proper current and the 
muscular current.—Elect. Mag., Vol. I, 1845, p. 20—2z2., 
3. Structure of Electro-precipitated Metals; by Warren Dexa Rove. 
—Mr. Rue shows that in copying an engraved plate by precipitation, the 
copy is imperfect along the centre of each groove or depressed line, the 
two parts though apparently joined, being not so in reality. This difficulty 
and the porosity proceeding from the crystalline texture of the deposit, 
may be remedied by thoroughly tinning it at the back as soon as the cast 
is removed from the matrix; the tin insinuates itself into a great number 
of the pores, and binds the whole firmly together. With the help of a lit- 
tle chloride of zinc the tinning is effected very readily, and it should be 
done without disturbing the structure by filing. Owing to the porous 
texture of electro-precipitated plates, they cannot be used for any purpose 
where strength is required.— Proceed. Chem. Soc., part 13, p. 300. 
4. Electric Sound.—M. Jacobi has constructed an acoustic telegraph, 
in which the sound resulting from the interruption of the electric current 
is repeated one hundred and fifty to two hundred times in a second. The 
sound produced is transmitted to a distance of fifteen miles, (twenty four 
kilometres.) —L Institut, No. 600, 25 Juin, 1845, p. 231. 
5. An Account of Compact Aluminum; by Prof. F. Wouter of Géot- 
tingen.—T he author has lately found, contrary to the results of his former 
‘researches on aluminum made eighteen years ago, that this metal is readi- 
ly fusible, and that in its reduction from the chloride of aluminum by 
means of potassium, it presents itself in the form of fused globules, gene- 
rally so small that their shape is not distinguishable under the microscope, 
although occasionally they are met with having a sensible diameter. He 
effects the reduction at once in a clay crucible, the bottom of which he 
covers with pellets of pure potassium, and places upon these the chloride 
of ammonium, covering the whole with chloride of potassium in powder. 
The crucible being then closed up, and heated in a coal fire, the reduc- 
tion is instantly effected. 
Fused aluminum has the color and lustre of polished tin; it continues 
perfectly white in the air; it is fully malleable, and the globules may be 
beaten out into the thinnest plates without cracking at the edges. It is 
entirely unmagnetic. In other respects the metal in this compact state 
has the properties which the author formerly ascribed to it—JLondon, 
Edinburgh, and Dublin Phil. Mag., May, 1845, pp. 450, 451. 
