British Association for the Ad/oancement of Science. 15 



eign countries, when treated in this manner, in the most perfect 

 state of heahh. Want of skill in the management of those 

 brought from alDroacl was the most frequent cause of injury. Too 

 much water was frequently given to plants when just packed. 

 They had better be placed in too dry, than in too moist an atmos- 

 phere. He had seen this illustrated in plants from India ; plants 

 exposed to too much moisture rotted very soon. He thought the 

 change of color in the leaves of plants depended on their free ex- 

 posure to light ; the Droseras mentioned had not been exposed to 

 the free access of light ; this was certainly the case with the- Dro- 

 seras at Chatsworth and of Mr. Gray. The discovery of Mr. 

 Ward was not only important in enabling us to import foreign 

 plants, but it also rendered the ventilation of green-houses less 

 necessary, and would enable gardeners to manage the artificial 

 climate of their hot-houses with less difficulty. The fact that 

 cellular plants grow best under this mode of treatment, was well 

 established. — In answer to a question from Prof. Lindley, Mr. 

 Gray and Mr. Yates stated, that plants had both liowered and 

 fruited under this plan of treatment. — Prof. Graham stated that 

 the order in which he had found plants to grow best, was, 1. Ly- 

 copodiums ; 2. Grasses ; and 3. Begonias. 



Raihvay Iron. — Mr. Mushet made some observations on Rail- 

 way Iron, founded on experiments carried on for forty years. He 

 expressed himself much surprised, that hitherto, in contracts for 

 iron for railway purposes, fibre and hardness were not stipulated 

 for, but were left to the chapter of accidents. Both these quali- 

 ties might be attained by his method, the principal characteristic 

 of which consisted in doing away with the refining process now 

 in general practice, and the preventing the severe decarbonization 

 to which the iron was at present exposed. Several specimens of 

 iron, of extremely fine fibre and hardness, were laid before the 

 Section, and afterwards removed to the Model Room. The great 

 object of his process was, to obviate the evil of lamination. On 

 some railroads they had been obliged to lay the iron two or three 

 times ; but he had little doubt, that it would soon be possible to 

 obtain a solid rail without any exfoliation. 



Mr. Cottam mentioned, that he had known a piece of iron six 

 inches thick, and considerably bent, to be quite straightened by 

 blows, but, at the same time, to be greatly weakened ; and that 

 he attributed this to some of its constituent crystals being driven 



