322 Chronicles of Science. [ April, 
ore in Sweden, and it is supposed that this is the first time that this 
metal has been found in English pig-iron. 
A note on the Quantitative Determination of Sulphur by Dr. D.S. 
Price,* deserves notice, as it draws attention to a source of error 
which is very liable to be overlooked by analysts. He finds that 
the ordinary method of estimating sulphur, by fusion with nitre over 
gas, 1s liable to error in consequence of the coal gas giving sulphur to 
the contents of the crucible. Experiments show that nitre, which 
before fusion was free from sulphur, contained an appreciable 
quantity after exposure to a gas flame for three quarters of an hour. 
Perhaps one of the most important problems in analytical 
chemistry is to obtain the reagents of that exceptional purity which 
is absolutely necessary in many researches. In _ toxicological 
inquiries it is, of course, of vital importance that the sulphuric acid 
should be free from that very common impurity arsenic, and chemists 
will on this account be glad to know of a method by which this difficult 
problemn can be solved. The method of distillation as ordinarily 
practised is of no value, but it may be made available with the modi- 
fications introduced by MM. Bussy and Buigne.t These chemists 
have shown that when the arsenic exists in the state of arsenious acid 
it distils over, but when it is present as arsenic acid the whole remains 
behind in the retort. Upon boiling the suspected acid with a little 
nitric acid, or, as Maxwell Lyte proposes,t by adding a little bichromate 
of potash and then distilling, the product will be perfectly free from 
arsenic. 
A new pigment, which appears likely to afford a ready means of 
preserving iron and other metals, has recently been introduced in 
Paris by M. Oudry, of the Auteuil electro-metallurgic works. Pure 
copper is first precipitated by the galvanic process, and it is then 
reduced to an impalpable powder. This powder is then mixed with 
a preparation of spirit and used as ordinary paint. The articles 
coated in this way have all the appearance of electro-bronze, while the 
cost is less than one-sixth ; it is likely to last from eight to ten years, 
and beautiful effects are produced by means of a dressing of acidified 
solutions and pure copper powder. 
A patent has recently been entered by M. Clavel for modifying the 
beautiful blue dyes obtained from coal tar, so as to render them 
soluble in water. He dissolves the dye in fuming sulphuric acid and 
then dilutes the solution considerably, passing steam im at the same 
time. The colouring matter is then precipitated in flocculi by the 
addition of common salt ; upon washing the salt out, the dye remains 
perfectly soluble in water. Whilst speaking of these aniline dyes we 
may mention with pleasure that the parent to whom they all owe their 
origin, Dr. Hofmann, has been honoured by the Jecker Prize of 5,000 
francs, given by the Paris Academy of Sciences, for his researches on 
artificial organic alkalies. 
* «Chemical News,’ viii. 285. 
+ ‘Journal de Pharmacie et de Chimie,’ xliv. 177. 
t ‘Chemical News,’ ix. 98, 
