448 KANSAS CITY REVIEW OF SCIENCE. 
These petroleum emulsions have been used with success by Dr. J. C. Neal, 
of Archer, Fla., against the Cotton Worm, without injury to the plant, but their 
chief value depends on their efficacy against the different scale-insects which affect 
Citrus plants. Experience so far shows that such plants do not suffer from its 
judicious use, but that it must be applied with much more care to most deciduous 
fruit trees in order not to injure them. 
GAS FROM SAW-DUST. 
" So far as we are aware," says the London Timber Trade Journal, "the 
making of illuminating-gas from saw-dust is a new branch of trade ; certainly it is 
one of considerable importance, from the fact that it deals with what, in the 
majority of cases, is a waste product. We are advised that Mr. R. Tomlinson, 
late manager of the Cottingham Gas-Works, near Hull, has just completed the 
erection of the gas-works and lighting the town of Deseronto, Ontario, Can., the 
works being erected for the purpose of making gas from fine saw-dust. The gas 
produced is said to be far superior to that made from the best Silkstone coal, and> 
to be equal to that made from the best cannel coal. It would appear that Mr.. 
Tomlinson is especially commissioned in the above matter, for we learn that upon 
the completion of some water mains, which he has also in hand, he intends return- 
ing to England. As a basis for the manufacture of illuminating gas, saw-dust 
lays claim to many specialties, more so in the wood-producing countries of north- 
ern Europe and America, where coal has to be obtained at great cost, and where 
saw-dust is a greater drug and nuisance than in our own country. As saw-dust 
can be practically applied to the manufacture of illuminating-gas, it is clear, 
where the supply is at hand, towns may be illuminated by it; but it strikes us as 
being applicable, in a smaller and more general degree, in the case of illuminat- 
ing saw-mills, joinery works and other establishments where saw-dust is pro- 
duced." 
THE MACKAY-BENNETT MARINE CABLES. 
Messrs. Siemens, of London, are energetically pushing the work on the new 
Mackay-Bennett cables, now being manufactured by them at Charlton Pier, Wool- 
wich. They will form a duplicate line from Ireland to Nova Scotia, continued 
from Nova Scotia by special cable to Cape Ann, and having a branch line from 
Ireland to France. The work was definitely begun last week, and though ma- 
terials are still being prepared and tested, yet it is already possible to determine 
the character of the cables. Their core will contain a strand of eleven copper 
wires of highest conductivity, weighing 350 pounds per nautical mile, and the 
dielectric will consist of eight coatings of gutta percha placed upon the wire 
according to the improved method of Messrs. Siemens, and weighing 300 pounds. 
