36 
THE GEOLOGIST. 
and Geoffroy St. Hilaire, and the Honorary Curator of the Museum of 
the Ethnological Society of London. Our space will not permit us to do 
more than record the fact, with the tribute of our admiration for the 
talents and labours of the deceased, and the expression of our conscious- 
ness that a school of scientific thought was founcled by him which will sur- 
vive when his faults and failings shall have been all forgotten. 
Deep Gold Diggings of Melbouene. — As the opinions expressed by 
Sir Eoderick Murchison (' Siluria,' 3rd edit. p. 488), that wlierever the 
veinstones in the solid rock have not been ground down by denudation, 
and remain as testimonials of the original seat of the gold, the portions 
which have as yet proved to be the richest are those which are at or 
nearest the surface, have been recently seemingly impugned by the ac- 
counts \N iiich have reached us respecting the deep quartz gold mines in 
Australia, — the following note, by Professor M'Coy, of Melbourne, gives an 
important confirmation of the correctness of Sir Koderick's original con- 
clusion. In a private letter, writing of the deep gold diggings of Mel- 
bourne, he makes these comments on them : — " SirE. Murchison's theory, 
which I have always upheld, of the ratio of gold in the quartz veins 
diminishing with the depth, is every day getting more support. You must 
be cautioned that so many ounces of gold, said to have been crushed from 
so many tons of quartz from deep mines, really means, that perhaps 1000 
tons may have been mined, and out of it 100 tons picked as rich enough 
to be sent to the mills ; so that the richness of the deep quartz is very 
different from what it would appear without this correction, which you 
must always ask after before you give up your correct position, yielding 
to the logic of supposed facts which are really capable of explanation." 
Canadian Petroleum. — The ' Canadian Journal of Art ' asserts that 
the Canadian petroleum is not derived from coal, nor is it of recent origin. 
It says : " Petroleum was formed long before the coal, and is the result of an 
infinite number of oil-jnelding animals which swarmed in the seas of the 
Devonian period long anterior to the coal. The decomposition of marine 
plants may have given some oil to the rocks of Canada and the United 
States which are saturated with this curious substance. The shale beds 
of Collingwood furnish an answer to those who object to the infinite num- 
ber of animals it would require to produce the oil locked up in the earth. 
These shale beds are composed altogether of the remains of trilobites ; 
they extend from Lake Huron to Lake Ontario, and from west and east 
of these lakes. The oil-bearing rocks of Canada were once a vast coral 
reef, extending from the Gulf of Mexico to Lake Superior." 
Iron Formed by Animalcules. — In the 'Journal de I'lnstruction 
Pablique,' M. Oscar de Watterville states that in the lakes of Sweden 
there are vast layers or banks of iron exclusively built up by animalcules. 
The iron thus found is called " lake ore," and is distinguished according 
to its form, into " gunpowder," " pearl," " money," or " cake " ore. These 
iron banks are often from 10 to 200 yards in length, 5 to 10 broad, 
and from 9 inches to a yard in thickness. In winter, the Swedish peasant, 
who has but little to do in that season, makes a hole in the ice of a lake, 
and with a long pole probes the bottom until he has found an iron bank ; 
an iron sieve is then let down, and with a sort of ladle conveniently 
fashioned for the purpose, the loose ore is shovelled into the sieve, which 
is then hoisted up again. The ore thus extracted is of course mixed 
up with sand and other extraneous matters, which is got rid of by 
washing in a cradle like that used by gold diggers. A man can turn out 
a ton of ore per day by this process." 
