COLOURS OF FLOWERS. 



329 



ARTIFICIAL COLOURING OF- FLOWERS. 



In a course of chemistry, the action exercised by sulphurous acid on 

 coloured vegetable matter is proved by exposing violets to the influence of 

 this gas, which whitens them instantaneously. Sulphurous acid, by its dis- 

 oxidating properties, destroys the colour of many flowers, such as roses, 

 periwinkles, etc. The experiment succeeds very readily by means of the 

 little apparatus which we give in fig. 317. We^ssplve in a small vessel 

 some sulphur, which ignites in contact with air, and gives rise, by. its com- 

 bination with oxygen, to sulphurous acid; the capsule is covered with a conical 



Fig. 318. Experiment for turning columbines a green 

 colour with ammoniacal ether. 



chimney, made out of a thin sheet of copper, and at the opening at the top 

 the flowers that are to be discoloured are placed. The action is very rapid, 

 and a few seconds only are necessary to render roses, periwinkles, and 

 violets absolutely white. 



M. Filpol, a distinguished savant, has exhibited to the members of the 

 Scientific Association, Paris, the results which he obtained by subjecting 

 flowers to the influence of a mixture of sulphuric ether and some drops of 

 ammonia ; he has shown that, tinder the influence of this liquid, a great 

 number of violets or roses turn a deep green. We have recently made on 

 this subject a series of experiments which we will here describe, and which 

 may be easily attempted by those of our readers who are interested in the 



