344 PROCEEDINGS OF THE 



The process of treating the green parts of plants, notably 

 flowering plants, with a solution of copper acetate dissolved in 

 strong acetic acid was proposed by Prof. Trail, and his direc- 

 tions for using a hot solution are now recognised as generally 

 the best method. The object of the process is to form per- 

 manent green compounds of chlorophyll and copper. The 

 fresher the plant the more successful will be the treatment. In 

 spring, when the leaves are young and active, the result is better 

 than in autumn. Deciduous-leaved plants, as a rule, green 

 quickly and well, while evergreens require protracted boiling, 

 some changing to brown at first, but after twenty to forty 

 minutes' boiling this gradually gives way to green. Glass or 

 porcelain vessels should be used for treating specimens with the 

 boiling solution. Drying after the process may be by pressure 

 in drying paper or in hot sand, the choice depending on the 

 texture of the plant. 



Dr. Rendle exhibited a large number of specimens of various 

 plants preserved by the method he had described. Some ferns 

 were particularly beautiful, the vivid green colour giving them 

 an extremely natural appearance. Liverworts, mosses and 

 selaginellas all retained a most life-like aspect. Specimens of red 

 seaweeds which had been permanently stained to represent the 

 natural colour were also shown ; and several specimens of flower* 

 which had been dried in hot sand or the Fothergill press, notably 

 a delphinium and a scarlet geranium, in which the brilliant colours 

 seemed altogether unchanged by the process of drying, in some 

 cases after an interval of many years ago. 



Mr. N. E. Brown then showed a number of dried herbarium 

 specimens, in most of which the colour was excellently kept, 

 although they had been prepared many years ago. He said 

 that it was evident that the means which proved successful in 

 one case might not answer in another, but he had found tliat 

 the best method was to carry through the drying process as 

 quickly as possible, and that it should be done at a somewhat 

 high temperature. 



Mr. F. J. Perks said he was sure the members would wish to 

 accord a hearty vote of thanks to the President for his interesting 

 and valuable address and for the trouble he had taken in bring- 

 ing the very beautiful specimens to the meeting. The proposal 

 was agreed to by acclamation. 



