230 
SCIENTIFIC PRINCIPLES OF GARDENING. 
of light rich earth, and then plunged in a very gentle bottom heat, under glass. 
These are horticultural facts, which I believe to be decidedly established ; and I also 
consider, that in all probability such plants, if every flower-bud be timely removed, 
can be preserved through the winter, in a dry stove, or well-aired and warm green- 
house. I am not, however, enabled to speak unhesitatingly on the latter particular, 
because I was not prepared to afford the desired shelter during November and the 
early part of December, as my house was in an unfinished state, and the pit in 
which the young plants were placed, was far too much exposed to early damps and 
hoar frosts. I have fully succeeded, however, in securing a succession of other 
tender, herbaceous, and annual plants, by cuttings taken off in September or 
October, among which I may mention particularly, one of the Coreopsis tinctoria ; 
this is now as fine and healthy a young plant as I ever beheld. I only wait for a 
favourable opportunity of prosecuting my inquiries, in order to furnish that infor- 
mation which may enable other horticulturalists to extend their researches, which if 
pursued with patience, and in a spirit of true philosophical investigation, may at no 
remote period of time lead to discoveries as interesting to the lovers of science, as 
they will be gratifying to those whose chief object it is to add to or extend the 
beauties of the greenhouse and flower garden. 
SCIENTIFIC PRINCIPLES OF GRAFTING. 
When the finger is cut with a knife the blood-vessels soon after contract 
their cut extremities into an opening so narrow, that the thicker and red-coloured 
part of the blood cannot pass, and the bleeding therefore ceases, but even then there 
oozes out the thinner watery part of the blood consisting chiefly of matter the same, 
or similar to the white of an egg, which being thus separated from the rest of the 
blood thickens by the heat of the body, as the white of an egg does by boiling. If 
the lips of the finger cut, accordingly, be kept close together by sticking-plaster they 
will become united by means of this natural glue, as it may be termed, in little 
more than a day, upon the same principle. When I was a student of medicine I 
once succeeded, as others have done, in managing to unite the whole top-joint of a 
finger which a boy had chopped off by machinery ; and experiments have been 
successful in causing the spur of a cock to unite and to grow upon his comb. It is 
upon similar principles that the science of grafting is founded; for if a young 
branch, like the boy's finger, be chopped off by a clean cut, and the cut extremities 
immediately joined, the descending pulp will thicken like the watery part of the 
blood, and while it remains soft the sap from the cut ends of the sap-vessels will 
force its way through to their continuation above in the cut slip, which, if the process 
be successfully managed, will grow as well, or nearly as well, as if it had never been cut. 
If again, instead of applying the same cut slip to the part it was cut from, a slip from 
another tree be applied, as if I had applied to the boy's finger the tip of another 
boy's chopped off by the same accident, there seems no good reason to doubt that a 
similar healthy joining might by care be effected ; in the case of animals, indeed, 
such joinings are rare, because rarely tried ; but in garden plants they are exceed- 
