PEOr. H. M. WARD AND MISS B. DALE ON CRATEROSTIGMA PUMILUM. 351 



is the behaviour of the red colour of our plant towards potash. The colour first becomes 

 a reddish purple and then a dull purplish or inky blue, but the pigment does not dissolve. 

 The contents of the cell also take on the same colour. AVitli nitric acid the colour 

 dissolves and forms a fluid which is coloured brownish pink. With acetic, chromic, and 

 hydrochloric acids the colour remains unchanged. In alcohol the pigment is extn^mely 

 soluble and forms a red solution with a yellowisli-brown or pink-browu tint. The colour 

 is also very soluble, and forms a red solution, in ether; but in benzol, carbon bisulphide, 

 and chloroform it is only slightly soluble. 



The results we obtained with G-asteria are essentially the same as those which Courchet 

 got with Aloe. 



The colouring-matter in Chamcedorea Sartorii in many of its reactions resembles 

 carotin, but in some of those in which it differs it behaves like the colour in Cratcro- 

 stigma. Both are extremely soluble in alcohol, whereas carotin is only slightly soluble. 

 But in CliamcBdorea this solution is followed by the formation of a finely divided vellow 

 precipitate. Both are very soluble in ether, and only slightly so in benzol and carbon 

 bisulphide. 



The reactions of the colour in Craterostigma all differ markedly from those of carotin ; 

 among these the different behaviour of the two bodies towards concentrated sulphuric 

 acid and towards iodine are specially noteworthy. In no single reaction does the red 

 colour behave exactly like carotin. On the whole, though some of the reactions differ 

 considerably, it is much more like that of Gasteria (or Aloii) than any other with which 

 we have compared it. 



With concentrated sulphuric acid Gasteria becomes first orange, then greenish yellow, 

 fading into pale yellow and quickly becoming colourless. Tiie changes of colour are so 

 various and so rapid that it is extremely difiicult to distinguish one from another and to 

 observe their sequence. With iodine the colour becomes a pale yellowish brown. These 

 reactions seem to be essentially tf\e same as those which occur when the red colour in 

 Craterostigma is treated w4th the same reagents. The difference is of degree rather ttian 

 of kind, and m:iy be due to the fact that the original colour of Gasteria is pale pink and 

 of Craterostigma a deep but bright red. 



With alcohol both are very soluble and form pink or red solutions. Both are only 

 partly and slowly soluble in benzol, carbon bisulphide, and chloroform, with which ttiey 

 form pink or red drops of fluid. They differ, however, in their solubility in ether. liic 

 red colour dissolves readily, the pigment in Gasteria is almost insoluble. Potash, w hich 

 with carotin and the colour in Chamcedorea gives no reaction, affects, but iti different 

 ways, both the colour in Craterostigma and in Gasteria. That in the former rapidly 

 becomes reddish purple, then a dull blue, while that in the latter slowly changes to a 

 yellowish brown. 



Hydrochloric acid with the red colour in our plant gives no reaction, but it changes 

 that in Gasteria into orange, which becomes yellow and then fades away. 



With nitric acid the red colour dissolves and forms a brown-pink solution, while that 

 in Gasteria behaves essentially like carotin and the colour in Chanuedorea ; the colour 

 first becomes yellowish, and then rapidly disappears. Carotin takes on a blue, and the 



SECOND SERIES. — BOTANY, VOL. V. 3 G 



