On Labarraque's Disinfecting Soda Liquid. [1827. 



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 of. 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. THE 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 



* Quarterly Journal of Science, xxiv. 84. 



