464 Scientific Intelligence. 
weight of iron, by its specific heat. In an example the coil had 
480 turns, the core weighed 832°5 grams, the current 70232, 
the unit being that required to set free 1 mgr. of h drogen a second, 
The 
pressure of the air increased 17°8 mm, of water, corresponding to a 
t @ generated 
was 0000174 units, and the value of m?/ was 1855: the unit being 
the amount requisite to repel an equal amount at distance of a 
with a force of a decigram. This gives the magnetic 
equivalent of heat=106,000,000 units of magnetic energy, approx- 
imately. Its true value is probably somewhat less since we have 
not here taken account of the heat transported by induction into 
the magnetizing coil, but have only taken care that it should be 
small.— Comptes Rendus, \xxix, 290. i: 0.’ P. 
2. Unilateral Conductivity.—Dr. A. Scuuster finds that certain 
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tion of the needle, a mirror, telescope and scale were used, an 
the delicacy of the galvanometer was such that an electro-motive 
of the seale. If now the wire to be tested was connected with the 
changed the effect. Repeating the experiment several 
general ishes the 
diminish deviation or causes it to disappea!, — 
—_ 
