Contributions to the Chemistry of Chlorophyll. 309 



For such as wish to prepare this substance, I may state, as the 

 result of my experience, that it can only be obtained from the faeces of 

 cows or other herbivora that have been fed exclusively on grass or 

 other green vegetable food ; those of stall-fed cattle, nourished as they 

 usually are to a great extent with oil cake, yield none, on account 

 perhaps of the large amount of fatty matter presentfin that case in 

 the faeces. I may add that the solid excrements of sheep that have 

 been at pasture for some time and living on herbage only, on being 

 treated as above described, yield the same substance, but I have made 

 no experiments with the faeces of other herbivora. I imagine that the 

 yield of this peculiar substance is greatest from material collected in 

 spring or early summer ; but this, if correct, may be due to other 

 causes than difference of season. 



This substance not having, so far as I can ascertain, been previously 

 observed, I propose to call Scatocyanin, a name kindly suggested to me 

 by Professor Wilkins, of Owens College. Its chief properties are as 

 follows : Under the microscope it appears in the form of thin 

 rhombic plates or elongated flat prismatic crystals, which are pale 

 brown by transmitted light, of a purplish-blue colour with a brilliant 

 metallic lustre by reflected light. When heated between watch- 

 glasses it is decomposed without melting or swelling much or yielding 

 any sublimate ; heated further on platinum, it burns away, leaving a 

 little ash. It is almost insoluble in boiling alcohol, ether, carbon 

 disulphide, and benzol, but it dissolves, though not readily, in chloro- 

 form, giving a solution which shows an absorption spectrum of five 

 bands, almost identical with those of phyllocyanin. It dissolves in 

 boiling glacial acetic acid, giving a fine crimson solution, which, when 

 sufficiently dilute, shows an absorption spectrum of four bands of 

 which the two first are well defined, the third faint with some obscura- 

 tion between it and the second band, the fourth band also faint and 

 not well defined (see fig.). From a saturated solution in boiling acetic 

 acid the substance separates on cooling and standing in lustrous pur- 

 plish-blue needles. 



It dissolves in concentrated sulphuric acid with a brilliant grass- 

 green colour, which, on standing, changes to purplish-blue. The 

 solution now shows a characteristic absorption spectrum of five bands, 

 of which the first and fifth are faint and poorly defined, the second and 

 third well defined, but the fourth only moderately so, while there is 

 much obscuration between the fourth and fifth bands, with just a trace 

 of a sixth band in the green between the fifth band and the total 

 obscuration (see fig.). 



The sulphuric-acid solution on being mixed with several times its 

 volume of water changes its colour from purplish-blue to a fine purple 

 without giving any precipitate and without showing any change in its 

 absorption spectrum. On standing, however, for some time the liquid 



