528 Chronicles of Science. [Oct., 



we recently referred, has distinguished two hodies soluble in water, 

 the one found in Phycochromacese, the other in Floridese in con- 

 junction with Chlorophyll, to the first of which he gives the name 

 Phycocyan, and to the second Phycoerythrin. These remarkable 

 bodies give very distinct absorption-bands when examined by 

 means of the spectroscope, and are also highly fluorescent, 

 Phycocyan giving a fine carmine reflection, whilst the light it 

 transmits is pale blue, and Phycoerythrin giving a yellow fluores- 

 cence, and transmitting the red rays. At a recent meeting of the 

 Microscopical Society of London, Mr. Sheppard exhibited a fluid, 

 having the properties of a solution of Phycocyan, which he had 

 obtained from a vegetable growth in a spring in Kent. He con- 

 tended that the colour was produced by the action of monads on 

 albuminous substances which he had placed in the water with the 

 vegetable matter. It appears, however, that the vegetable en- 

 crustation abounded in Oscillariae, Batrachospermum, &c, and from 

 the drawings and description given of the spectrum of the fluid 

 and its fluorescence, there is no doubt that he had simply obtained 

 a solution of the Phycocyan of Dr. Ferdinand Cohn. The colouring 

 matters of the lower forms of plants and their relations to Chloro- 

 phyll and the physiology of plant-life form a very important and 

 almost unexplored field of research. 



5. CHEMISTEY. 



(Including the Proceedings of the Chemical Society.) 



But few papers call for notice on this occasion. The subject of 

 water-analysis continues to attract a good deal of attention; and 

 additional interest has been given to the matter by the communica- 

 tions of Professor Wanklyn and Messrs. Chapman and Smith. The 

 first-named gentleman read a paper on the subject at the last 

 meeting of the Chemical Society, an abstract of which will be 

 found in our report of the Proceedings of the Society. Several 

 joint communications have also been made to the ' Laboratory' 

 during the past three months. 



The researches of the gentlemen named have been devoted to 

 the determination of ammonia and matters capable of yielding 

 ammonia ; and their results differ widely from those of other ex- 

 perimenters. We are told, for example, that the waters we have 

 hitherto been taught to consider the purest and best fitted for town 

 supplies, such as Loch Katrine and Bala Lake water, contain a 

 larger amount of albumenoid putrescible matters than the waters 

 at present supplied to the metropolis. Thus, quoting from Pro- 



