SCIENTIFIC SUMMARY. 
101 
the chlorine into such solution while hot. The stream of chlorine is stopped 
when a little of the fluid neutralized with potash no longer gives a green 
precipitate with bichromate of potash ; thus showing that all the arsenious 
acid has been converted. The hydrochloric acid may then be recovered by 
distillation, and the syrupy solution of arsenic acid left in the retort eva 
porated. — Yide Chemical News. 
The Nature of White Phosphorus . — The researches of M. Baudrimont tend 
to prove that white phosphorus is neither a hydrate nor an allotropic condition 
of the ordinary element ; that it does not result from a devitrification of trans- 
parent phosphorus, but that it is simply ordinary phosphorus corroded on 
the surface by the action of air dissolved in water, — a slow combustion, which 
is accelerated by the action of light, and ceases when all the oxygen is 
removed. M. Baudrimont has found that phosphorus covered with a white 
crust lost very little in drying, while a stick of transparent phosphorus 
exposed in distilled water lost weight as it became covered with the crust. 
If the crust had been a hydrate, an increase of weight would have been 
observed. On becoming covered with the crust, phosphorus loses none of its 
properties ; its solubility and fusion-point remain exactly the same, and it is 
as readily transformed into red phosphorus. Hence it would appear that 
nothing like an allotropic difference is observable. Lastly, it is shown 
that water deprived of air and oxygen has no effect on semi-transparent phos- 
phorus, while other specimens kept in water containing air, and often 
renewed, become covered with the white crust, the water becoming acid from 
the formation of phosphorous acid. — Vide Comptes Pendus, Nov. 13. 
Cheap Mode of Producing Oxygen . — The ordinary methods of obtaining 
oxygen are attended with so much expense that chemists will gladly learn 
that a new method for the production of this gas upon a large scale has been 
spoken of. Indeed a company has been started in Paris for the purpose of " 
supplying oxygen at the rate of about threepence per cubic foot, which is 
hardly a fiftieth of the present cost. The oxygen is obtained by acting on 
sulphate of lime with silex in a furnace of peculiar construction, the results 
being silicate of lime, sulphurous acid, and oxygen — 
Si 2 0 3 + CaO,SO* = Ca0,Si0 3 + S0 3 + 0 
The gaseous mixture is conducted into a chamber, where it is exposed to a 
pressure of three atmospheres, which liquefies the sulphurous acid ; the 
oxygen is purified by transmission through lime-water, and then compressed. 
How to test Otto of Boses. — A method is suggested by ITagar, which consists 
in mixing five drops of the suspected oil with twehty drops of concentrated 
sulphuric acid. Whether the oil be adulterated or not, a thick yellowish- 
brown or reddish-brown mixture results. When this mixture is cold, it is 
shaken up with three drachms of absolute alcohol. If now the otto is pure, 
a tolerably clear yellowish-brown solution results, which, after heating to 
boiling, remains clear ; but if the otto is adulterated with geranium, palm- 
rose, or pelargonium oil, the solution remains very cloudy, and in some cases 
a darker fluid separates, in which a deposit forms. On heating this solution, 
the sediment melts together, and from the size of the mass the author infers 
the degree of adulteration. If, for example, the mass has on e-fourth the volume 
