1866. | Chemistry. 577 
alumina, to account for the facts on which Svanberg based his 
fancied discovery. A variety of researches by R. Hermann on the 
rarer earths will be found in No. 6 of the ‘Journal fiir praktische 
Chemie’ for this year. 
Dr. Rudolph Wagner has found that the rare metal Indium is 
to be met with in the flue dust of zine ovens, where indeed it 
might naturally be looked for. The fact is worth mentioning, and 
we believe it would repay a chemist to examine the flue dust 
wherever blende is roasted. 
The same author has also published a process for the extraction 
of mercury from poor cinnabars, partly in the moist way. He 
treats the ore with a hot solution of sulphide of barium, which 
dissolves the sulphide of mercury, to be precipitated again by the 
addition of hydrochloric acid. The sulphide so obtained can be 
reduced or used directly for the preparation of mercurial salts, 
Incidentally the author gives a process that can be applied to the 
valuation of the ore. Cinnabar he finds is in the course of a day 
or two completely decomposed by a solution of iodine in iodide of 
potassium, iodide of mercury being formed, and sulphur set free. 
The difference in the amount of free iodine, ascertained by means 
of hyposulphite of soda, will show how much has combined with 
mercury, and consequently how much mercury is present. 
M. Roussin has suggested the use of the metal Magnesium in 
toxicological examinations. It rapidly and completely precipitates 
the poisonous metals without the risk of introducing another to 
complicate or falsify the results. It can also be used in a Marsh's 
apparatus in place of zinc with the utmost confidence, since it has 
been shown by Professor Wanklyn, as well as by M. Roussin, that 
commercial magnesium is perfectly pure. 
We have in former numbers mentioned the new analyses of 
Harrogate waters, and may here add that further investigations by 
Dr. Muspratt and Mr. R. H. Davies have revealed the presence of 
lithia and strontia in all the springs. Mr. Davis has found as 
much as 3°242 grains of carbonate of strontia in a gallon of the 
water of the Old Sulphur Well, and 2-815 grains in the Kissingen 
spring. The amount of lithia has not been determined; but its 
presence has been recognized by means of the spectroscope. Con- 
tinual changes seem to be taking place in the saline constituents of 
the Harrogate waters, barium salts, together with the strontia, and 
probably the lithia having appeared within the last few years. No 
one of these bodies was detected by Dr. Hofmann in 1854. 
One of the most important papers on technical Chemistry pub- 
lished during the past quarter is the second part of the Memoir of 
M. Kolb “On the Manufacture of Soda by Leblanc’s Process.” As 
this is a most important branch of industry in this country, where 
upwards of a thousand tons of common salt are daily consumed in 
