368 APPENDIX. [No. XXXIV. 



by placing wires over plants in the hope that electricity might be excited, 

 but they were all useless. I have myself kept plants under considerable 

 tension in a room in a house, but I could see no effect whatever, and I 

 may fairly say that we have not the remotest notion of the way in which 

 electricity will affect a plant. But we see what electricity will do in the 

 violent discharge which takes place in a thunderstorm : if a tree is struck, 

 the lightning goes down it just under the bark, and then jumps to the 

 ground where it is wet or damp, so that the bark of the tree is peeled off, 

 and this is one of the common effects of an electric discharge on a growing 

 tree. I have the figure of a tree which was struck in the grounds of a 

 friend of mine. It stood in a field where some hurdles were placed, and 

 the electric discharge could be traced from the tree to a point where these 

 hurdles entered the ground. This may be taken as the effect of lightning 

 upon a tree. Those stories which we hear of trees dying because struck 

 by lightning are merely fables ; and as far as I have seen, in many in- 

 stances the effect which is produced is that the bark is thrown off and 

 torn and loosened all round the tree. With regard to the immediate 

 effects produced by electricity on the growth of plants, nothing is known, 

 and in my opinion it has no important effect on vegetation at all. 



But having a knowledge of these forces and even using them aright, 

 the plant will not grow unless put in proper earth. A peach in a pot will 

 never bear fruit unless you have hammered down the earth about its roots 

 as hard as you can, and one great expense in growing these plants is that 

 a great many pots are broken by the force which has to be applied in thus 

 hammering the earth. The mallet is used so that the roots come in 

 contact with the earth, and then the plant will do well. 



Now the camellia, treated in the same way, will surely die, for the 

 roots of the camellia require a more porous earth, and the distribution of 

 the material among them should be light and peaty. I may mention that 

 in Florence, where the camellia was first introduced into Europe from 

 Japan by a monk of the name of Camella, they grow their plants in rotten 

 chestnut wood, and in that only. I was very much struck with this, and 

 in one garden the gardener said, " Yes, when I receive plants from your 

 country, I shake off all the stuff you put them in and change the soil." I 

 have tried camellias in various soils. If you put them in loam, it will kill 

 them. I have tried them in rotten wood and tan, and find them to grow 

 admirably well. This shows the necessity for a particular sort of soil to 

 the growth of a plant. It must have certain ingredients, and these ought 

 to be sought for in the analysis of the ashes of the plant. Our knowledge 

 on this point is in a most imperfect state, but we may say that almost and 

 perhaps all plants require a certain amount of phosphates and a certain 

 amount of potash. These are essential. There are other particular 

 materials in specific plants. The grasses require a large amount of flint 

 in their composition. Other plants require other definite salts, but potash 

 and lime seem to be required by all, and it would be as impossible to 

 grow them without these bodies as it would be to grow them without 

 light and heat. 



Now this brings us to another point; how are plants nourished? 

 They are nourished from certain constituents of the atmosphere. A 

 certain amount of carbonic acid exists in the air, and it is from that that 

 the fibre of a plant is made. With regard to the nitrogenous materials 



