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MOTES AMD ABSTRACTS IN CHEMISTRY AND PHARMACY. 
Syrup of Iodide of Iron and its Preservation. 
M. Jeannel, taking advantage of the power glucose possesses to reduce a per- 
salt of iron at ordinary temperatures, recommends the following formula for the 
preparation of a solution of iodide of iron which shall remain unchanged by 
exposure to the air. 
Iodine.8 - 2 parts. 
Iron filings.TO ,, 
Distilled water. 20 0 ,, 
Honey. 70’0 ,, 
Tartaric acid.0 5 ,, 
Mix the iodine, iron, and water, in a flask, and when combination is complete, 
filter the green solution, and add the honey and tartaric acid. The product will 
contain 10 per cent, of iodide of iron. This preparation, after remaining ex¬ 
posed to the air in a phial simply closed with paper for two months, was still 
bright and free from colour. It contained no free iodine, or ferric salt. 
M. Jeannel has observed that the addition of one five-thousandth part of tar¬ 
taric acid to syrup of iodide of iron, which has become bad, renders it clear and, 
at the same time, notably diminishes its inky taste. 
The Purification of Sulphide of Carbon. 
M. Miilon recommends the following method for purifying sulphide of carbon : 
•—The sulphide is first washed several times with water, and then introduced into 
a large retort with a quantity of quicklime. After twenty-four hours’ contact, 
the sulphide is distilled from the lime, and received in a flask containing a large 
quantity of copper turnings, which have been previously calcined to remove 
organic matters, and then reduced by heating in a current of hydrogen. 
The lime from -which the sulphide has been distilled is deeply coloured, and 
resembles crude soda ash in appearance. The sulphide of carbon thus purified 
has an ethereal odour, which, if not actually agreeable, is quite different from 
the offensive smell of commercial sulphide. It is with sulphide of carbon thus 
purified that MM. Miilon and Cominaille have separated the perfume of the 
most delicate flowers, and from cows’ milk have been able to recognize the 
odours of plants eaten by the animals. 
A New Test for SSydrocyanic Acid in Vapour. 
M. Schonbein has given to the French Academy of Medicine a description of 
a new and extremely delicate reagent for the detection of hydrocyanic acid in 
the state of vapour. It consists of paper imbued with resin of guaiacum, and 
moistened with a solution of sulphate of copper at the moment of use. In con¬ 
tact with hydrocyanic acid, the prepared paper immediately assumes a blue 
colour. Three parts of resin of guaiacum are dissolved in a hundred parts of 
rectified spirit. White filtering-paper is steeped in this solution and dried. 
The paper should remain wdfite. A solution is prepared of one part of sulphate 
of copper in five hundred parts of water. To employ the test, a slip of the paper 
is moistened wfith this solution of sulphate of copper, and brought in contact 
with hydrocyanic acid, either dissolved in water or diffused in the air, when it 
immediately becomes blue. The sensitiveness of the reaction is shown by the 
following experiments :— 
A single drop of a solution of hydrocyanic acid containing 1 per cent, of real 
acid, is placed in a vase of 20 litres capacity. A strip of the prepared paper is 
suspended by a wire in the middle of the vase, which is then covered. The 
blue tint rapidly becomes apparent. A drop measures -Ath of a cubic centimetre, 
and the vase holds 20 litres, or 20,000 cubic centimetres ; consequently, therela- 
