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222 its temperature. Thus the heat is actually taken up by the gas from one end of the cylinder, and conveyed to the other, occasioning the difference of temperature spoken oil The effect is best observed when, as before stated, the gas, at a pressure of thirty atmospheres, is suddenly let into the vessels: the capacity of the recipients is such, that the pressure usually sinks to about ten atmospheres.

Experiments on the nature of Labarraque's Disinfecting Soda Liquid.

1. following experimental investigations relate to the nature of that medicinal preparation which M. Labarraque has lately introduced to the world, and named Chloride of oxide of Sodium. They were occasioned by the accounts which were given of this and other substances of similar power to the Members of the Royal Institution, at two of their Friday evening meetings; the value of the preparation, the uncertainty of its nature, and the inaccuracy of its name, all urging the inquiry.

2. In the first instance the inquiry was directed to the nature of the action exerted by chlorine gas upon a solution of carbonate of soda, questions having arisen in the minds of many, whether it was or was not identical with the action exerted by the same gas on a solution of the caustic alkali, and whether carbonic acid was evolved during the operation or not. Chlorine gas was therefore carefully prepared, and after being washed was sent into a solution of carbonate of soda, in the proportions directed by M. Labarraque: i. e. 2800 grains of crystallized carbonate of soda were dissolved in 1.28 pint of water; and being put into a Woulfe's apparatus, two-thirds of the chlorine evolved from a mixture of 967 grains of salt with 750 grains of oxide of manganese, when acted upon by 967 grains of oil of vitriol, previously diluted with 750 grains of water, were passed into it; the remaining third being partly dissolved in the washing water, and partly retained in the open space of the retort and washing vessel. The operation was conducted slowly, that as little muriatic acid as possible might