HORTICULTURAL SOCIETY OF LONDON. 



295 



was removed with scarcely a leaf remaining. Another healthy 

 plant was then placed in the same circumstances, and suffered 

 in the same manner, though not so rapidly as the first. 



No. 3, had no preparation of any kind under the hand-glass, 

 and the plant here continued to grow throughout the whole time 

 of the experiments without suffering in any way, further than 

 by being drawn up, and by having its top injured by the pressure 

 of the hand-glass. 



No. 4. The diluted muriatic acid had a most beneficial effect 

 upon the Balsam in this hand-glass j it grew more luxuriantly 

 than any of the others, and the weeds in the pot vegetated and 

 flourished in a very remarkable manner. Further, as before re- 

 marked, — the sickly leafless plant, brought here from No. 1, 

 gradually recovered, and was soon in a high state of health. 



The plants in Nos. 5 and 6, where the dry calomel and dry 

 corrosive sublimate were, did not seem to be at all affected until 

 about the 15th of June, and then only slightly j if this was 

 owing to the nature of these compounds, their action must have 

 been very slow. 



In all these cases the atmosphere contaminated by mercury 

 proved deleterious, affecting the plants by making the leaves curl 

 at the edges and become dry and yellow. The vapour of muriatic 

 acid however revived them and made them grow with unusual 

 vigour. 



The effects produced by the shavings of Kyanized wood were 

 somewhat similar, and agree with other observations which have 

 been made elsewhere. A frame was formed of this wood for the 

 growth of Melons in the garden of the Society, but it was found 

 impossible to succeed with it. In the Gardeners' Magazine for 

 Sept. 1839, Earl Manvers states, that he had some rafters 

 " steeped in the solution, at the strength of one gallon of corro- 

 sive subhmate to ten gallons of water," and that the effects 

 upon vegetable life were of the most injurious kind, three fine 

 healthy vines being killed and the condition of the others being 

 much affected. And finally, Messrs. Loddiges of Hackney, were in- 

 duced to use it upon a considerable scale in rafters for their 

 Orchidaceous house, and for many other buildings in their ex- 

 tensive nursery, where its bad effects were soon discernible ; 

 and if they had not been counteracted by painting over the 

 wood, many of the valuable plants in that establishment would 

 no doubt have been destroyed. In fact, after the lapse of se\"eral 

 years they are still obliged to paint it frequently to prevent any 

 bad effects. 



From these experiments it seems that we may safely arrive at 

 the following conclusions. 1st. That the vapours which arise 



