SCIENTIFIC SUMMARY. 
455 
listed in the Comptes Rendus from the pen of Dr. T. L. Phipson, in which 
the author points out what he considers to he a simple mode of ascertaining 
the presence of bromine and iodine in the same solution. The method is 
based on the fact that in the presence of sulphide of carbon and free chlo- 
rine, iodides are first decomposed and afterwards the bromides, and further, 
that the chlorine acts upon the iodine dissolved in the sulphide of carbon 
to form quinti-chloride of iodine, which dissolves, and leaves the sulphide 
of carbon colourless. If bromides be present, the sulphide of carbon as- 
sumes an orange colour. 
Chlorine and Manganese have been combined by M. Nicies in such pro- 
portions as to form a deuto-chloride, which is, however, a less permanent 
salt than the other haloid combination of this base. 
The Impurities of the New (?) Ancesthetic. — In a paper read before the 
British Medical Association at its meeting in August, Dr. Protheroe Smith 
read a paper on Tetrachloride of Carbon, in which he gave the following 
directions for the detection of its three impurities. These are as follow : — 
1. Bisidphide of Carbon. — This is easily detected by evaporating over a 
spirit-lamp a portion of the suspected fluid in a deep cup, when, if it 
contains bisulphide, a slightly bluish flame will appear, whereas if free 
from this impurity it would be entirely uninflamable. 2. Free Sulphur . — 
Should such exist, after spontaneous evaporation of some of the tetrachloride 
on a watch-glass, a fine opaque film will remain, which when heated would 
give off the well-known fumes of sulphurous acid. 8. A peculiar sul- 
phur-compound, which is discovered by dipping in the suspected fluid some 
clean blotting-paper, which when dry will give a peculiar unpleasant smell 
of dirty linen. 
A New Cement — Oxychloride of Magnesium. — At a late meeting of the 
Drench Academy, M. Dumas called attention to a new manufacture of M. 
Sorel’s, a cement produced by combining chloride of magnesium with oxide 
of magnesium, and possessing, as does the oxychloride of zinc, in a degree 
incomparably greater than plaster of Paris, the property of not only taking 
all variety of forms, but of solidifying and taking a high polish. Experi- 
ments made two years ago leave no doubt as to the good quality of stones 
prepared by this process, and the absolute resistance, of objects so fabricated 
and moulded, to the deleterious action of water. u Industry and art will 
therefore enter into possession of new elements of construction and trans- 
formation. The chloride of magnesium that can be extracted from sea- 
water, or which is found in great quantities solidified in interior seas as that 
of Stassfurth, does not require to be entirely pure, and costs less than the 
oxychloride of zinc.” 
Estimation of Lime in Analysis. — At a meeting of the Drench Academy, M. 
Boussingault communicated a new mode of finding the quantities of lime 
in analysis. The process consists in precipitating the lime in the state of 
sulphate, which is decomposed either by a Bunsen gas blowpipe, or by one 
of Schlosing’s furnaces, the sulphuric acid being vaporised, and the lime 
remaining pure. In several experiments on the decomposition of earthy or 
metallic sulphates, M. Boussingault remarked frequent anomalies, the quan- 
tity of the base remaining often being less than it ought to be. The fact is 
not easy to account for. 
