xi MURIATIC ACID AND CHLORINE 213 



the gas " unites with water in very small quantity ; and gives 

 to water a slightly acid taste ; but as soon as it comes in 

 contact with a combustible matter it becomes again a proper 

 marine acid." As usually prepared it contained a certain 

 quantity of acid vapour, but this could be got rid of by 

 collecting it in wet bottles ; the acid was then dissolved by 

 the water, whilst the greater part of the chlorine remained 

 as a gas, into which various substances could be plunged. 

 The following properties were noticed : 



" The corks in the bottles became yellow, as from aqua 

 fortis." 



" Blue litmus paper became almost white ; all vegetable 

 flowers red, blue, and yellow became white in a short time; 

 the same thing also occurred with green plants. In the 

 meantime the water in the bottle became changed to a weak 

 and pure marine acid. The former colours of these flowers, 

 as well as those of the green plants, could not be restored 

 either by alkalis or by acids." 



" Iron filings were put into the same bottle and they 

 dissolved. This solution was evaporated to dryness and 

 distilled with an addition of oil of vitriol, when a pure 

 marine acid, which did not dissolve gold, again passed 

 over." 



" All metals were attacked, and with gold it is noteworthy 

 that its solution in this dephlogisticated marine acid forms 

 with volatile alkali a fulminating gold'." 1 



" Insects immediately died in the vapours ; and fire was 

 immediately extinguished by them " (A.C.R. XIII. 8-9). 



Berthollet (1785) regards chlorine as an oxygen com- 

 pound. Chlorine was next investigated by the French 

 chemist Berthollet (Mem. Acad. Sa., 1785, 276-295 ; A.C.R. 

 XIII. 11-31), who made a special study of the properties 

 of CHLORINE-WATER. This was prepared by passing the 

 gas through a series of bottles ; the first bottle, empty and 

 cold, served to condense and remove the acid vapours ; 



1 See Chapter XII. 



