Miscellaneous Intelligence. 441 
for contrary winds and rough weather, a. large amount of surplus power . 
is indispensable. In fair weather it is not difficult to attend to all these 
5. Permeability of Iron.—Our readers may recollect our having, some 
months ago, mentioned certain experiments made by MM. H. Sainte- 
Claire Deville and Troost, from which it appeared that, by a kind of en- 
Osis scarcely to be suspected in the case of a metal, hydrogen would 
Pass through the pores of a platinum tube. Last week, the Academy of 
Sciences received from them a new paper, in which they announce a 
amilar property in iron. The great difficulty was to find a tube answer- 
} to the various conditions required for the experiment. The iron 
hot admit of being tempered. It was in reality rather iron than steel, 
and so soft that it was drawn into a tube without heating or soldering, © 
though its sides were of a thickness of from three to four millimetres. 
To the ends of this tube, two other tubes of a much smaller diameter, 
and of copper, were soldered with silver; the whole was then introduced 
into an Open porcelain tube, which was put into a furnace ; a glass tube, 
s tablis , i ne- 
ig hydrogen completely deprived of atmospheric air; while at the 
he end, another glass tube, bent at right angles, dipped into a mercury 
bath, its vertical branch being 80 centimetres long. For the space of 
ho 
Tatus, which was maintained at a high temperature, so as to exhaust the 
hee of the hydrogen on the sides of the iron tube, and to drive away 
ike” atmospheric air, as well as the moisture contained in the tube, or 
i a be produced there. This done, the communication between the 
apt tube and the hydrogen apparatus was cut off by melting down the 
slss tube by the aid of the blowpipe. No sooner was this effected, than 
Ax. Jour, Sct.—Szconp Senres, Vou. XXXVII, No. 111.—Mar, 1864. 
57 
