125 
RICHARDSON AND BERZELIUS’S ANALYSIS OF WOLFRAM. 
Yttria is not altered by having a current 
of sulphuretted hydrogen passed over it while 
heated to redness in a green glass tube. 
When phosphorus in vapour is passed oyer 
yttria heated to redness, a vivid ignition 
takes place, but no combination is formed. 
The weight of the yttria remains unaltered. 
To he continued. 
ANALYSIS OF WOLFRAM. 
By Mr. Thomas Richardson. 
In 1781 Scheele discovered a peculiar sub- 
stance in a heavy white mineral found in 
Sweden, to which he gave the name of Tungs- 
tic acid base being called Tungsten from 
its weight. Shortly after this Messrs. 
D’Elhuyart obtained the same acid in a 
mineral called by the Germans wolfram, 
which had been analyzed in 1761 by Lehmann, 
who considered it to be a compound of iron 
and tin. Weigleb and Klaproth also analyzed 
this mineral, but nothing can with any con- 
fidence be drawn from their result, both of 
them having a deficiency of upwards of 21 per 
cent. Vauquelin repeated the experiments 
of the Elhuyarts in 1796, and obtained the 
following : Tungstic acid, 67.00 Protoxide of 
manganese 6*25, Protoxide of iron 18’00, 
Silica 1 •50,92*75, Part of the iron Vauquelin 
supposes to be in the state of peroxide. But 
even if this supposition were adopted there 
would still be too great deficiency to warrant 
us in drawing any conclusion from the ana- 
lysis. Berzelius published a set of experi- 
ments upon tungsten in 1815, and states the 
composition of this mineral to be according to 
his analysis : Tungstic acid 74*666 Protoxide 
of manganese 5*640, Protoxide of iron 17*954, 
Silica 2*100,100*000. The quantity of tung- 
stic acid was determined from the loss, which 
prevents us from placing so much confidence 
in it as we could otherwise have done, from 
the known dexterity and precision of the 
analyst. 
This mineral occurs generally along with 
tinstone, in veins and beds ; it is met with 
also traversing greywacke, with ores of lead, 
&c. It is found in almost all the Saxon and 
Bohemian tin mines, as also in several places 
in Cornwall. 
It is thus found in France : In Siberia it 
occurs accompanying the emerald, and also 
in the United States of North America. 
It occurs massive, and often crystallized. 
The primary form being a right oblique 
angled prism. The specimen subjected to 
analysis was from Zinnwald, in Bohemia, 
and seemed perfectly pure. 
It possessed the following characters : — 
Foliated ; not very brittle ; fracture une- 
ven ; streak, reddish brown ; colour, blueish 
black ; lustre, approaching metallic ; opa- 
que ; hardness, 5*0 to 5*5 ; sp. gr. 7*017. 
Before the blowpipe, decrepitates when 
heated alone, but may be melted in a high 
temperature into a globule, possessing the 
metallic lustre. 
With soda, on platinum wire, it fuses into 
an opaque green coloured bead in the oxydiz- 
ing flame, which changes to pink in the 
reducing flame ; with borax fuses easily into a 
transparent red coloured in the oxydizing 
flame, which becomes pale yellow in the 
redueing flame. With salt of phosphorus fuses 
readily into a transparent yellow coloured 
bead in the oxydizing flame, which becomes 
red in the reducing flame. On adding a small 
piece of tin to this red coloured bead and con- 
tinuing the flame for a short time the 
colour changed to green. 
It was analyzed in the following way ; — 
A. 20. grs. of the mineral, in fine pow- 
der, were kept fused with 60 grs. of carbo- 
nate of soda (anhydrous) for half an hour. 
The whole, upon cooling, was digested in 
water for 48 hours. The insoluble portion 
which remained behind was separated by a 
filter, and well washed with distilled water. 
The solution which came through the filter, 
together with the washings, being evaporated 
to a convenient bulk, pure nitric acid was 
added, and the tungstic acid precipitated of a 
beautiful yellow colour. After being well 
washed with distilled water, acidulated with 
nitric acid, dried and ignited, it weighed 
14*39 grs., or 71*95 per cent. 
B. The undissolved portion which remained 
on the filter in (A.) was dissolved off by 
muriatic acid, and the solution neutralized as 
exactly as possible with carbonate of am- 
monia. The whole was now boiled with 
benzoate of ammonia in a flask on the sand- 
bath, and the benzoate of iron which it pre- 
cipitated was separated by a filter. After being 
clean washed, dried and ignited, the peroxide 
of iron which remained weighed 2.58 grs.= 
2.362 grs. protoxide of iron. 
C. The solution and washings from (B.) 
being evaporated to dryness, the whole was 
exposed to a red heat, to get rid of the am- 
moniacal salts. What remained was dissolved 
in water, and boiled with carbonate of 
soda. The manganese which precipitated 
was separated by a filter, and after being well 
washed, dried, and ignited, weighed 3.37 grs. 
red oxide = 3.137 protoxide of manganese. 
Hence, we have for the composition as 
follows *. — Tungstic acid 14.390 or 71.950 
Protoxide of iron 2,362 ,, 11.810 Protoxide 
of manganese 3.137 ,, 15.985 Total 19.889 
99.445 
The difference between this and the pre- 
ceding analysis of Berzelius induced me to 
make another, and the result of the second, 
executed, in the same way, gave as follows : — 
Tungstic acid 73*60, Protoxide of iron 1 1*20, 
Protoxide of manganese 15*75. Total 100*55. 
Agreeing with the first very nearly except in 
the quantity of tungstic acid. 
If we adopt Dr. Thomson’s atomic weight 
of tungstic acid, as given in the last Edition 
of his System of Chemistry, and calculate, we 
obtain the following: — 
atoms. 
Tungstic acid 4*74 or 1*90 
Protoxide of iron 2*49 ,, 1*00 
Protoxide of manganese. . . 3*50 ,, 1*40 
Which approaches very nearly the following 
formula ; 
