12 
ago Professor Prestwick explained his reasons for believing that 
coal existed at no very great depth, in the south east of England, 
thus linking the coalfields of Somerset with those of Belgiam and 
France, and establishing the geologieal fact of the subterranean 
connection of the Mendips with the Ardennes. Whether the coal 
in Kent is sufficiently valuable in kind or abundant in quantity to 
pay for the working, has not yet been fully ascertained 
The various and great industries in connection with petroleum 
are remarkable for having been entirely developed during the last 
thirty years. It was not till 1859 that the first petroleam well was 
drilled in America, and in that year five thousand barrels were pro- 
duced ; last year the yield was twenty-one million five hundred 
thousand barrels! In Russia, where crude petroleum is largely 
used as fucl for locomotives, many million gallons are used ia 
working the railway traffic on the Caspian Sea; in Russia alone, 
three million tons of petroleum are produced yearly, In America 
the natural gas furnished by the oil fields is extensively used, and 
in Pittsburg three hundred and thirty-five miles of pipes have been 
laid down, through which this natural gas is supplied, and which 
equals in heating power three million six hundred and fifty tons of 
coal. The effect of this change from coal gas to natural gas on 
the purity of the atmosphere is most marked. Water gas, in com- 
bination with a certain proportion of a very luminous coal gas, is 
now extensively used in New York, Philadelphia, and other large 
towns in America, and is found to be far purer and better, both for 
illuminating and heatirg purposes, than the ordinary coal gas. 
An interesting discussion has been going on in the French Academy 
of Science, as to the nature of the diamond, M. Daubree asserting 
that it is not of vegetable origin, but of imorganic nature, like 
graphite, which is found in South Africa in the same rocks as the 
diamond. The presence of the diamond as carbonado (as well as 
transformed into graphite) in fragments of meteorites, lends great 
weight to this assertion. A curious chemical achievement has just 
been accomplished by Mr. Greville Williams, of manufacturing a 
perfect emerald from the refuse of a gas retort. The cost, however, 
of producing it is ten times as great as if it were bought at a 
jewellers. In 1837 M. Gaudin. produced real rubies by artificial 
means, and some ten years ago Mr, Hannay, of Glasgow, succeeded 
in manufacturing genuine diamonds, but in all these cases the cost 
has been prohibitive, and the processes, though of great scientific 
interest, are of no commercial value. It is for this same reason, 7.e. 
the cost of production, that Saccharin is commercially valueless, 
although it is two hundred times as sweet as sugar. 
It would really almost seemas though one of the functions of 
science is to make us unlearn all that we learned in our youth 
