USEFUL PROJECTS. 
Observations on the grafting of Trees. 
In a Letter from Thomas Andrew 
Knight, Esq. to Sir Joseph Banks, 
Bart.from the Philosophical Trans- 
actions. 
Dir: 
I AM encouraged to address the 
following letter to you, by the 
Opinion you were last year pleased 
to express of part of my experi- 
ments and observations, on the dis- 
eases and decay of those varieties of 
the apple and pear which have been 
long in cultivation. The disease, 
from whose ravages they suffer most 
is the canker, the effects of which 
are generally first seen in the winter, 
or when the sap is first rising in the 
spring. The bark becomes disco- 
loured in spots, under which the 
wood, in the annual shoots, is dead 
.to the centre, and in the older 
branches, to the depth of the last 
summer’s growth. Previous tomak- 
ing any experiments, I had cons 
versed with several planters, who 
entertained an opinion, that it was 
impossible to obtain healthy trees of 
-those varieties which flourished in 
the beginning and middle of the 
present century, and which now 
form the largest orehards in this 
country. The appearance of the 
young trees, which I had seen, jus- 
"tified the conclusion they had drawn ; 
but the silence of every writer on 
the subject of planting, which had 
come in my way, conyinced me 
that it was a vulgar error, and the 
following experiments were under- 
taken to prove it so. 
I suspected that the appearance 
of decay in the trees I had seen 
Jately grafted, arose from the diseas- 
ed state of the grafts, and concluded 
that if { took scions or buds from 
[*89 
trees grafted in the year preceding, 
I should succeed in propagating any 
kind I chose. With this view, I in- 
serted some cuttings of the best wood 
I could find in the old trees, on 
young stocks raised from seed. [I 
again inserted grafts and buds taken 
from these on other young stocks, 
and, wishing to get rid of all con- 
nection with the old trees, I repeat- 
ed this six years; each year taking 
the young shoots from the trees last 
grafted. Stocks of different kinds 
were tried, some were double graft- 
ed, others obtained from apple- 
trees which grew from cuttings, and 
others from the seed of each kind of 
fruit afterwards inserted on them; 
I was surprised to find that many of 
these stocks inherited all the diseases 
of the parent trees. 
The wood appearing perfect and 
healthy in many of my last grafted 
trees, I flattered myself that I had 
succeeded; but my old enemies, the 
moss and canker, in three years 
convinced me of my mistake. Some 
of them, however, trained to a 
south wall, escaped all their diseases, 
and seemed (like invalids) to enjoy 
the benefit of a better climate. I 
had before frequently observed, that 
all the old fruits suffered least in 
warm situations, where the soil was 
not unfavourable, I tried the ef, 
fects of laying one kind, but ‘the 
canker destroyed it at the ground. 
Indeed I had no hopes of success 
from this method, as I had observed 
that several sorts, which had always 
been propagated from cuttings, 
were as much diseased as any otbers, 
The wood of all the old fruits” has 
long appeared to me to possess less 
elasticity and hardness, and to feel 
more soft and spongy under the 
knife, than that of the new varie- 
ties which I have obtained trom 
seed. 
