DISEASES AND AFFECTIONS OP PLANTS. 
203 
matter in the act of fermentation and putrefaction has lately given rise to the opinion 
that these actions themselves, and the changes suffered hy the bodies subjected to 
them, are produced in consequence of the development of fungi, or of microscopical 
animals, the germs or eggs of which are supposed to be diffused everywhere, in a 
manner inappreciable to our senses : they are supposed to be developed when they 
meet with a medium fitted to afford them nourishment. Several philosophers have 
ascribed to this circumstance the fermentation of wort, and of the juice of the grape." 
As to the remedy, we know of none that is worthy of reliance. Sulphur (flowers 
of brimstone) forcibly driven over peaches, or their leaves, by a spring puff, with a 
fine wire-gauze orifice, is stated to be effectual ; but we cannot vouch for the certainty 
of the remedy, nor yet for that of the sulphuretted ivash, made by pouring a gallon or 
two of boiling water upon a pound or more lime, unslaked, and fresh from the kiln, 
mixed with four ounces of sulphur. The yellow fluid — a sulphuret of lime — 
syringed, when cold, over mildewed leaves, or into the hearts of pine-apple plants 
infested with the scale, is certainly remedial to some extent, but cannot be regarded 
as specific. 
Enough, perhaps, has been written upon the subject of parasites to arouse a spirit 
of more active research ; and as something remains to be said upon the attacks of frost, 
and of insects, we offer the following observations : — 
The present year has been as remarkable for its meteoric phenomena as was its 
predecessor. The winter of 1844-5 was rigorous almost beyond precedent, and con- 
sistently so, till the 20th of March. The whole of the corresponding period of 
1845-6 was mild to such a degree as to permit the Fuchsias of the open garden to 
push new flowering shoots from the old stems, without covering or protection of any 
kind. These are great enjoyments in a mild winter, particularly if January be dry 
and sunny, as it occasionally is in our southern counties ; operations of all kinds can 
then be performed, ground prepared, and (what is a great comfort) the forcing gar- 
dener is relieved in one of his most arduous duties — night-forcing ; but winters of 
so mild a character as that of the present year, have their disagreeable contingencies ; 
and the first we shall allude to is the injury to tender, early developments, by a sud- 
den access of frost, though its duration be that of a few hours only. Thus, after an 
average temperature far above that of freezing, with blossoms fully expanded, a frost 
of 6 degrees, on the 19th morning of March, paralysed all the plum and apricot 
bloom, and produced a total loss. 
The second severe infliction was the attack of Aphis or green-fly on the Rose, 
which, during two months, converted the bushes and standard trees into masses of 
deformity. We have before seen the plants ravaged to a vexatious extent, but never 
can we retrace anything of the kind so pertinacious. Upon this subject we have 
nothing to advance theoretically, as to causes ; and the effects speak for themselves. 
As a remedy for every species of the ordinary Aphis of the garden and greenhouse, 
the gardener may place confidence in tobacco smoke, provided he can efficiently apply 
it ; but there lies the difficulty. So long as a house or pit can be closed, and its 
