SCIENTIFIC SUMMAKY. 
217 
be rendered habitable and comfortable. The experiments were attended by 
a very large number of persons, representing the principal engineering and 
shipping firms, and also by many owners of steam yachts, who are desirous 
of using the new fuel instead of coal. — Vide the Times. 
Oil-io ells in Baden have been recently discovered, and are said to be as 
productive as the American springs. The oil is reported to be excellent. 
The locality of the wells is Wiesloch. 
Gun-cotton as a Blasting Material. — We learn that experiments have 
recently been made in one of the Yorkshire coal-mines as to the value of 
this substance as a substitute for gunpowder. It appears from the trials 
already made, that, besides the superiority in power of gun-cotton over gun- 
powder, it possesses — what in a coal-mine is most important — the property 
of emitting no flame. Hence it can be used in cases in which the employ- 
ment of gunpowder would be positively dangerous. 
The Separation of Lead from Argentiferous Lead Ore. — The French cor- 
respondent of the Chemical Neios , who displays a wonderful faculty for col- 
lecting and popularising the most recent scientific news, states thatM. Cordure 
has been more skilful than his predecessors, inasmuch as he has made use 
of the affinity which lead has for silver, in order to extract the former from 
the above-named ore. When the argentiferous lead is melted, a small 
quantity of zinc is added, and, after an energetic brushing, the mixture is 
allowed to repose. The alloy of zinc and silver, being lighter than lead, 
rises to the surface, and, as it is less fusible, it cools sooner. By watching 
the proper moment the silver can be skimmed off, united with zinc and a 
small quantity of lead. The zinc and the lead are separated by remelting 
the skimmed mass, and oxidising, by means of a current of hot air or super- 
heated steam, and treating afterwards with hydrochloric acid ; the residue is 
submitted to cupellation. Nothing hinders the chloride from being utilised 
in its actual state, or being transformed into carbonate of zinc. 
Prevention of Accidents from Fire-damp.— The explosions which now so 
often occur in our mines are terribly destructive of life and property ) but, 
strange to say, if they were much more frequent they would be less dan- 
gerous. If, in fact, the gases were caused to explode before they have 
collected in any large quantity, no serious damage would result. This is the 
principle of the remedy proposed to the French Academy by M. Somonet. 
He suggests the introduction into all the “ drifts ” of electrical conducting 
wires, so that the inflammable gases may be set on fire by interruption of 
the electric current before time has been given for them to collect to any 
dangerous extent. 
Neio Reactions of the Oxide of Tungsten. — It has been pointed out by Mr. 
Skey, of the New Zealand Geological Society, that there are other reactions 
of tungsten than those already indicated in books. If, for example, he says, 
tungstic acid is made red-hot, and then brought in contact with a cold sur- 
face, it becomes permanently black. This is due to the formation of an 
oxide. The hot acid dropped into kerosene oil gives rise to the same effect. 
The addition of acetic or tartaric acid prevents the blue precipitate of oxide 
(resulting from the deoxidising of the acid by zinc) from being thrown 
down and dissolves it, thus forming a characteristic blue solution. 
Crucibles for Metallurgic Operations. — For inquiries in which a very high 
r 2 
