90 
POPULAH SCIENCE KEVIEW. 
be. We believe that the air examined by the chemists in question '^'as 
taken from the tunnels after several thousand square feet of opening had 
been made, to allow the foul gases to escape ; and if this view be correct, of 
course the analyses presented to the court were practically valueless, so far 
as they represented the atmosphere by which the death of the woman on 
whom the inquest was held was correct. Then again we find that our well- 
conducted and cautious contemporary, the Chemical News, is quite dissatisfied 
with the manner in which the analyses of the air were carried out. In an 
editorial article of some length, the writer states in reference to the discre- 
pancies in the evidence — We have here two views of the case, not agreeing 
very well with each other, although not in all points contradictory. Both, 
however, agree in drawing conclusions favourable to the air of the railway. 
For ourselves, we are unable to draw any such scdisfactory cojichisions ; the 
analyses are not clear. Are we to look on the average air as containing only 
five or six parts of carbonic acid per 10,000, or are we to consider that it has 
lost seven or eight tenths of a per cent, of oxygen, which would indicate a 
larger amount of carbonic acid ? Or, again, are we to believe that there is 
too little sulphurous acid to do us injury, or five times more than is needful 
to make us cough ? All these questions still remain unanswered, and yet 
the companies are believed by many to have made an excellent case.” 
A New Test for Alkalies is said to have been discovered by Herr Bottger. 
Indeed the test is supposed to be applicable to both alkalies and alkaline 
earths, and is based upon certain changes of colour produced by these ele- 
ments in the colouring matter of the leaves of Coleus Versehaffeltii. The 
re-agent is prepared by digesting the fully-developed leaves of this plant in 
alcohol, and impregnating slips of Swedish filtering paper with the solution 
obtained. This test-paper is of a beautiful red colour, which becomes green 
under the influence of an alkali or alkaline earth. It is not affected by free 
carbonic acid, so that it may be used for detecting traces of carbonate of 
lime in water. — Vide Jour. Soc. of Arts, Nov. 22. 
Solubility of Iodine in Organic Substances. — According to a paper read before 
the Vienna Academy of Science, by Herr Hlasiwetz, iodine is extremely soluble 
in many organic substances. It dissolves to a considerable extent in aqueous 
solutions of resorein, orein, or phloroglucin, without imparting to them any 
colour. These solutions may be boiled without iodine being volatilised ; 
they have almost neutral reaction, and starch, or carbonic bisulphide, does 
not indicate free iodine. A solution of the latter in alcohol or carbonic 
bisulphide is decolorised by adding one of the organic bodies mentioned, 
which may therefore be used in place of sulphurous acid in volumetric 
determinations by means of iodine. Other organic substances have been 
observed to behave in a similar but less decided manner. — Akad. Wien, 231, 
1867, and Chemical Neios, Sept. 29. 
Estimation of Organic Matter in Water. — M. Bellamy recommends as a rough 
but tolerably accurate mode of calculating the quantity of organic matter 
present in water, the use of sub-sulphate of alumina. When this re-agent 
is added to water which contains organic impurity, a precipitate is thrown 
down which is of a triple nature, being due to the influence of the quantity 
of water, of earthy bicarbonates, and of organic matter. The latter is 
deposited in a few hours, surrounded by the alumina with wdiich it has 
