158 
ON THE ACTION OF CHARCOAL ON VEGETATION. 
BY EDWARD LUCAS.* 
In a division of a low hothouse in the botanical garden at Munich, 
a bed was set apart for young tropical plants, but instead of being 
filled with tan, as is usually the case, it was filled with the 
powder of charcoal, (a material which could be easily procured,) 
the large pieces of charcoal having been previously separated by 
means of a sieve. The heat was conducted by means of a tube of 
white iron into a hollow space in this bed, and distributed a gentle 
warmth, sufficient to have caused tan to enter into a state of fer¬ 
mentation. The plants placed in this bed of charcoal quickly 
vegetated, and acquired a healthy appearance. Now, as always is 
the case in such beds, the roots of many of the plants penetrated 
through the holes in the bottom of the pots, and spread themselves 
out; but these plants evidently surpassed in vigour and general 
luxuriance plants grown in the common way,—for example, in tan. 
Several of them, of which I shall only specify the beautiful 
Thunbergia alata, and the genus Pereskia , throve quite astonish¬ 
ingly ; the blossoms of the former were so rich that all who saw it 
affirmed they had never before seen such a specimen. It produced 
also a number of seeds without any artificial aid, while in most 
cases it is necessary to apply the pollen by the hand. The PeresJcia 
grew so vigorously, that the P. aculeata produced shoots several 
ells in length, and the P. grandifolia acquired leaves of a foot in 
length. These facts, as well as the quick germination of the seeds 
which had been scattered spontaneously, and the abundant appear¬ 
ance of young Filices, naturally attracted my attention, and I was 
gradually led to a series of experiments, the results of which may 
not be uninteresting : for, besides being of practical use in the 
cultivation of most plants, they demonstrate also several facts of 
importance to physiology. 
The first experiment which naturally suggested itself was, to 
mix a certain proportion of charcoal with the earth in which dif¬ 
ferent plants grew, and to increase its quantity according as the 
advantage of the method was perceived. An addition of two- 
thirds of charcoal, for example, to vegetable mould, appeared to 
* A communication read by Mr. James Allen Ransome, at the Royal 
Victoria Gallery, Manchester. 
