190 TEAK-BOOK OF FACTS. 



Magent. Mr. Coleman's, which is somewhat different, is called 

 Dianthine. The colouring matter, which is a liquid, is applicable 

 in dyeing worsted, silk, and cotton. In the finer shades, as crimson 

 and rose, cochineal, it is said, cannot approach it in brilliancy ; and 

 even saffron yields a tint flat and thin compared with the new ele- 

 ment. The shades range from a deep purple to a brilliant rose. The 

 great object the dyers have now iu view is to discover some mordant 

 that shall perfect the process. 



A new species of red dye more brilliant than any hitherto produced, 

 and, above all, more solid than the Lest Chinese reds, has been dis- 

 covered at Lyons. The colour is said to be particularly soft to the 

 eye — something between scarlet and ponceau — the peculiar red 

 beheld in the small garden-flower, the "blood of Adonis." It is 

 already highly appreciated as "rouge sublime." 



FLOWER- COLOURING. 



Dr. George Lawson, in a paper read to the Royal Botanical So- 

 ciety <>f Edinburgh, says of Flower- colours : — " Our knowledge of the 

 chemistry of these colouring matters is still very imperfect. Chlo- 

 rophyll is not known in a state of purity, and the ehanges of colour 

 which it undergoes, have been only partially explained. By Fremy 

 and Cloez the colouring matters of flowers are referred to three 

 distinct substances, two of which are yellow, while the other is of a 

 blue or rose colour. The blue or rose colour is produced by a com- 

 pound which has been termed Cyanine, the blue tint becoming red 

 when exposed to the action of an acid. The yellow matter, which is 

 insoluble in water, is termed xanthine, and that which is soluble has 

 received the name of xantheine. These bodies, however, have not 

 been isolated in a pure condition ; and some of the facts above 

 recorded indicate at least a probability that three such bodies are 

 insufficient to account for all the observed phenomena of flower- 

 colouring." — Edinb. New Philos. Journal. 



INFLUUNCE OF SUN-LIGHT ON AMYLACEOUS SUBSTANCES. 



NlBPOH DB Saint- Victor and Corvisart (Comptcs Retuhu) de- 



BOribe the following instances of the peculiar influence which the 



Sunlight exerts in modifying and changing Amylaceous Sub- 



i : — 



If two 1 per cent, solutions of starch be prepared under the same 



(rircun •-■ of them be kept in the dark and the other 



l to the Bunlight, the latter will be Fo rt an action 



on the polarizing apparatus ; more dextrine and sugar have 



been formed. If very weak solutions be taken (about ■ „',-,,-. ) and 



1 to the sunlight for about eighteen hours, it will be found 



that the solution has lost the pn liginal amvlum, 



and more resembles inuline. 



h as lactate or oitrateof iron, and cot. 

 sublimate, limit or neutralise this action of the tight; while other 

 substances, such as potassio- tartrate of iron, or nitrate of urauium, 

 greatly increase it. 



