SCIENTIFIC SUMMARY. 
271 
the fourth generation, one of the great-grandchildren was father to twins 
one of which exhibited the webbed condition of the right foot which was 
presented by her great-grandmother, and also to a boy, whose right hand 
was webbed like that of his father. There are three strange facts brought 
forward here. (1) The entire absence of the peculiarity in the first gene- 
ration ; (2) the infirmity was confined to the eldest children ; and (3) 
it only affected the right side of the body. 
METALLURGY AND MINING. 
Asphalt Oil a Substitute for Coal. — This idea has been suggested in an 
important memoir reproduced in the Trinidad Colonist by a Mr. Stoll- 
meyer. There is in one portion of the island of Trinidad, and not above a 
mile from the shore, a basin of asphalt, which extends over an area 
of nearly a hundred acres. Besides this, there are numerous springs of a 
similar nature in the neighbourhood. Now it has been calculated that the 
lake is capable of supplying several hundred millions of gallons of oil, 
there being about seventy gallons of pure oil obtained from every ton of 
asphalt. As about forty-five gallons of the oil are equivalent to a ton of 
coals, it follows that the time required in loading a ship with oil would not 
be at all as great as in the case of coals, and moreover the necessary quan- 
tity of oil for consumption would not occupy nearly so large a space. It 
is, however, questionable whether the method he suggests the employment 
of, in order to obtain combustion, is a satisfactory one. 
Waste of Coal is the subject of a very interesting article from Professor 
Ansted’s pen, in the November number of the Mining and Smelting 
Magazine. He looks upon the eventual exhaustion of our coal-beds as 
likely to arise from other causes than those alluded to by Sir William 
Armstrong in his late address. There is the justifiable and the unjustifiable 
expenditure of this important mineral. It is to the latter especially that 
Professor Ansted draws his readers’ attention. Waste of coal takes place 
in three different ways. First : Waste of whole beds of coal. It is by no 
means unusual in certain mining districts to sacrifice an overlying seam of 
tolerable coal if that beneath it is of more value, and pays better ; the 
result of which is that as soon as the lower seam has been exhausted, the 
upper one becomes valueless, because, being unsupported, it cannot be 
worked. Even wheffthere is a solid roof, the coal becomes cracked through, 
and admitting both water and gas, is no longer workable in a pecuniary 
point of view. Second : Waste of seams a foot thick above, and others of 
the same depth below, which are employed to support the roof and floor, 
which might have been done by artificial means. Again, large pillars of 
coal are often allowed to be crushed to powder in order to avoid the expense 
of the heavy timbering and stone walls which would be necessary to prevent 
it. “ In some cases, nearly or quite one half of a valuable seam is thus 
sacrificed.” Third : Waste, as small-coal or dust, which is regarded as 
valueless, and is either left within the pit or at its mouth. This might be 
easily utilized, and is employed in other countries ; and the waste of this 
kind occurring in “tender” coal is hardly conceivable. It is sometimes 
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