xviii Proceedings. {November i6tli, 1915. 



Experiments were described in which comparison was made 

 between the bleaching activities of hypochlorous acid and 

 chlorine, the conclusion arrived at being that, contrary to the 

 general opinion, the latter is considerably the more active of the 

 two. 



The remarkable effect of a very dilute solution of chlorine 

 on litmus was shown. The litmus is at once turned a bright 

 red colour, which rapidly changes back to purple, and this slowly 

 bleaches. From this result Mr. Taylor concludes that the usual 

 explanation of the bleaching action of chlorine (in the case of 

 litmus, at any rate) is not correct, but that the chlorine acts by 

 directly chlorinating the colouring matter. 



Reference was also made to the recent use of hypochlorous 

 acid as the " ideal antiseptic." Professor Lorrain Smith uses 

 either a powder, which he calls " Eupad," made by intimately 

 mixing powdered bleaching powder and boric acid, or a solution 

 obtained by treating the powder with water, and which he calls 

 " Eusol/' In both the moistened powder and the solution as 

 used by Professor Lorrain Smith there will be a considerable 

 amount of hypochlorous acid ; but there will also inevitably be a 

 certain amount of free chlorine. Dr. A. Carroll and. Mr. H. 

 Dakin, who have apparently arrived independently at the same 

 conclusion as to the great value of hypochlorous acid as an 

 antiseptic, recommend the use of bleaching powder mixed with 

 boric acid and carbonate of lime. The use of the last-named 

 substance would have the effect of getting rid of most, if not 

 all, of the free chlorine referred to above. 



General Meeting, November 16th, 19 15. 



The President, Professor Sydney J. Hickson, M.A., D.Sc, 

 F.R.S., in the Chair. 



Mr. Donald Ward Cutler, B.A. (Cantab.), Scholar of 

 Queens' College, Cambridge, Assistant Lecturer and Demonstrator 



