Magnetism by Voltaic Electricity. 283 
the coal which alternate with this sand stone. If the coal 
formation, eXists as a portion of the old red sand stone, we 
can entertain no reasonable doubt that the old red sand 
stone itself was formed after the earth was covered with wood, 
and if it turn out to be true, as there is some reason for be- 
lieving that the transition and some of the primitive rocks, 
alternate with the old red sandstone, we must conclude that 
these rocks also have been formed after the ears’ was cov- 
ered with wood.—Thomson’s Annals, Nov. 1821. 
42, Spontancous Combustion. 
A barrel of coat-mieal whiolivad been left = a recess of 
the chimney of a house in Glasgow, took fire = the fam- 
ily were absent at bathing quarters last summe 
remained but the iron hoops of the barrel and a ee w pieces 
of charcoal. ‘The meal was probably a little moist. ioe 
43.) Magnetism produced by V slice Electricity. 
A new and i interesting discovery has been made in relation 
oe the connexion between te Seectiuiee. obs Gs vanism. 
eee =" 
properties to bars er steel. Ir steel bars or ets be capa to 
the Galvanic current, placed in the direction of the magnetic 
axis, no effect follows ; but if they be placed parallel with the 
magnetic equator, they become magnetic, the end placed to 
the west becoming the north pole of the new magnet, and 
that toward the east the south pole. The galvanic “influence 
is So great in this respect as to exert its power ata distance 
egies inches ‘so that if the s 
b ed in a circle round the course of galve nic ¢ Cur-" 
rent, bast 808 kept paral to me magnetic a u 
comes : 
wire, or under i it, or on its. sides, become permanent ig i 
onthe dise. ° 
t 
