xiv Proceedings. S^December i6th,igij. 



bleaching power of the ordinary bleaching agents the kind of 

 colouring matter has to be been taken into account. Colouring 

 matters such as indigo and turkey-red are rapidly and com- 

 pletely bleached by either chlorine or hypochlorous acid, the 

 former being on the whole the more active of the two. A 

 solution of bleaching - powder, which is naturally strongly 

 alkaline, acts very slowly indeed upon the above colouring 

 matters. In ordinary unbleached linen, cotton, and jute, there 

 appear to be two quite different kinds of colouring matter, one 

 resembling those mentioned above, and rapidly bleached by 

 chlorine and hypochlorous acid, while the other is quite 

 unaffected by these bleaching agents, but is bleached by a 

 solution of a hypochlorite containing little, if any, free alkali. 

 The proportion of these two kinds of colouring matter varies. 

 In linen and jute a considerable amount of the colouring 

 matter is not affected by chlorine or hypochlorous acid, while 

 in cotton the proportion unbleached by these agents is very 

 small indeed. Still, cotton is not completely bleached by either 

 chlorine or hypochlorous acid, even after prolonged exposure 

 to those agents. 



General Meeting, January r3th, 1914. 



The President, Mr. Fr.^ncis Nicholson, F.Z.S., 

 in the Chair. 



Mr. William Charles Jenkins, Curator of the Godlee 

 Observatory, the Municipal School of Technology, Manchester, 

 was elected an Ordinary Member of the Society. 



