SCIENTIFIC SUMMARY. 
471 
secretion of the Salamandra maculata has been chemically examined by M. 
Zalesky. M. Zalesky has succeeded in isolating the active principle, which is 
an amorphous colourless mass soluble in water. M. Zalesky calls it salaman- 
drine , and states that it possesses, in an intense degree, the poisonous 
properties of the secretion from which it is extracted. 
METALLURGY, MINERALOGY, AND MINING. 
Aluminium Bronze in Machinery . — M. Hulot, of the French Imperial Mint, 
has called attention to the fact that the perforating tools employed in the 
division of postage-stamp s t are rapidly blunted by the gum used to render 
the stamp adhesive. Indeed, so rapidly is the effect produced, that after a 
few hours’ work the tools, instead of piercing the paper, only crush it. M. 
Hulot replaces the steel by aluminium-bronze at 10 per cent., and the new 
tool, striking 126,000 blows per day, or 180,000,000 holes, has worked for 
several months without need of repairs. Aluminium-bronze does not unite 
freely with spider by the old process ; but if we take equal quantities of 
zinc-amalgam and common solder, aluminium-bronze can be admirably sol- 
dered together by it. This solder becomes better, again, if it is alloyed with 
once or twice its weight of tin. Thus there are three excellent solders — 
1st, solder with half its weight of amalgam ; 2nd, with a fourth ; 3rd, 
with an eighth. 
The Manufacture of Zinc. — A paper on the relative value of the Belgian 
and Silesian processes for the manufacture of zinc has lately appeared in 
the Berg- und llutten-Zeitung (1867, No. 24). From this it appears that 
the Belgian furnaces, with sixty retorts, in seven or eight horizontal rows, 
require less fuel, have a more intense heat, a quicker process, and a greater 
yield, than the Silesian apparatus. On the other hand, the Silesian 
furnaces require less skilful workmen, but burn a smaller quantity of coal. 
The Silesian process extracts more zinc from the ore, whilst the Belgian 
furnaces have for a given time a greater productiveness. When the ore 
forms tough slags, the Silesian method is preferable. 
The Economisation of Sulphurous Acid in Copper Smelting. — At the late 
meeting of the British Association, Mr. P. Spence gave an account of a pro- 
cess for saving the sulphurous acid, which seems likely to come into use. 
The following is the plan adopted : — In the calcining furnace sulphur and 
arsenic are dissipated into the air, but a portion of the sulphur remains, 
which in the smelting furnace sinks below the silicate of iron, to be run off 
with the copper, and afterwards, when the regulus is again calcined, more of 
the sulphur is given off. By catching this vapour of sulphur in a draught 
of heated air passed along the furnaces, the sulphurous acid which is formed 
is introduced into the leading chambers, when it is converted into sulphuric 
acid. 
The Perseberg Iron Mines , Sweden . — Dr. C. Le Neve Foster read a paper 
on the above, before the British Association at Dundee. The author de- 
scribed some important deposits of magnetic iron-ore which are now being 
worked near Philipstadt, in Sweden. The ore occurs in beds, which follow 
