Chemical Notices :—M. Bernoulli on Tungsten. 293 
malleable. The addition of 15 per cent. of acid yielded an alloy 
which might be considered as steel. It was very hard, but was 
not sufficiently malleable. With 20 per cent. the hardness was 
still greater, but the malleability much less. 
The iron in these experiments was grey iron, and contained a 
considerable quantity of graphite, and it was found that with 
white iron a different result was obtained. The experiments 
were made in the same way as the previous ones; it was found 
that an alloy was only formed when charcoal dust was added ; 
otherwise the tungstic acid sintered together, and very little tung- 
sten combined with the iron, The alloy obtained with the addi 
tion of charcoal had none of the appearance of steel; it was 
white on fracture, had the structure of the iron used, and was 
imperfectly malleable. 
With an addition of tungstic acid in the proportion of 75 per 
cent. no regulus was obtained. Analogous experiments were 
made with the minerals Wolfram and Scheelite, and similar 
results were obtained. The manganese present in Wolfram exerted 
a considerable influence on the result ; and with Scheelite the 
lime combines with the silica to form a slag, so that the alloy is 
purer. 
It follows from these experiments, that it is not the carbon 
present in the iron in a state of chemical combination which 
reduces the tungstic acid, but that which is mechanically inter- 
mingled. From white east iron no carbon is withdrawn by the 
tungstic acid, and accordingly no steel is obtained if charcoal be 
not added. 
The waste cast-iron turnings of the workshop may hence be 
used for preparing directly a cast steel, to which the tungsten 
imparts great hardness; or if the iron does not contain too 
much sulphur, phosphorus, or silica, a very useful rough cast 
steel may be obtained by fusing it directly with a quantity of 
powdered Wolfram proportionate to the per-centage of carbon 
which it contains. 
The author determined the carbon in these alloys by three 
methods. In the first, a piece of the alloy was laid upon a fused 
cake of chloride of silver, and was left for several days, covered 
with distilled water. In this way the iron gradually dissolved ; 
and when the decomposition was complete, the charcoal and 
tungsten were collected on an asbestos filter, dried and weighed, 
and then the carbon determined in the usual way by combustion 
with oxide of copper. In another case the alloy was decomposed 
by chloride of copper, and in a third case it was digested with 
iodine until the iron was dissolved. In these cases the carbon 
contained in the alloy amounted to about 1 per cent. 
Kxperiments to alloy tungsten with other metals were also 
