THE MEDITERRANEAN NATURALIST 
24:* 
been suggested by the Commission, which if faith- 
fully followed, and methodically carried out will 
assuredly rid the islands in a comparatively short 
period of time of this most pernicious plant. 
Unlike many of the diseases to which Malta plant 
life is subject, that caused by the Peronospora 
viticola is amenable to a method of treatment 
which is at once cheap, easily applied, and effect- 
ive. The disease has been in existence in France 
and Northern Italy for many years, and as the 
governments of those countries have expended 
vast sums of money on experimental research 
having for its object the most efficacions means 
for combatting this disease, we have the addition- 
al advantage of having their experiments and 
experience to guide us. The result of their work 
has been to prove that there is but one effective 
remedy at present known, and that is sulphate of 
copper; and that although sulphate of copper is a 
strong poison no apprehension need be felt in using 
it, for if used in the proportions recommended it 
is quite harmless. Lime, sulphur, charcoal and a 
variety of other materials have been tried, but as 
a specific against the disease they are all worthless. 
Sulphur has been used on the vines in these 
islands for many years as a cure for the Oidium 
(black rot) and the erinosa, for both of which dis- 
eases it is a good remedy, but for Peronospora it 
is absolutely useless and the sooner the Maltese 
vinegrower recognises this fact the better it will be 
for his pocket. 
The sulphate of copper is a very cheap chemical 
It may be applied either in a dry state or in a 
liquid form. To apply in a dry state a powder 
consisting of 3 parts of sulphate of copper and 97 
parts of sulphur (or charcoal) should be throughly 
mixed together and afterwards scattered over the 
foliage of the plants by means of pair of bellows, 
or with a tin-can having a perforated head. Either 
sulphur or charcoal may be used, as it is only of 
service as a carrier for the sulphate of copper. 
The prohibitive prices of sulphur in Malta will 
perhaps suggest the use of the alternative, charcoal, 
which, besides performing the functions of a carrier 
will also improve the soil, and free the plants from 
insects. 
The liquid form is however the one to be the 
most strongly recommended. The following very 
simple mode of mixture has been proposed in the 
report of the commissioners. 
1. A half an ounce of sulphate of copper (blue 
vitrol) to be dissolved in a pint bottle of water. 
2. A half an ounce of slacked lime to be 
thoroughly shaken trp in a bottle containing an 
equal quantity of water. 
3. Mix the two thoroughly together so as to 
form a perfectly homogeneous liquid, and then add 
to it sufficient water to make up to one eight of a 
barrel known in the vernacular as one quarta. 
This mixture should then be sprayed on the 
plants by means of common garden syringes, or 
with the combination pump and syringe which 
has been specially constructed for the purpose. 
Among the poorer agriculturists of Sicily, to 
whom the expense of purchasing such instruments 
as these is an unsurmountable obstacle in the 
way of their adopting this mode of treatment, I saw 
a novel but most simple substitute, which, though it 
necessitated the expenditure of a much longer time 
in the application of the mixture, was, I was as- 
sured equally as efficacious. The modus operands 
was as follows. The mixture was carried among tin: 
vines in wooden buckets. Into it the operative 
dipped a large brush, such as that which is com- 
monly used for white washing, and by means of 
an upward, followed by a sharp downward move 
ment of the arm the contents of the brush were 
sprinkled over every portion of the foliage. It is a 
method that should recommend itself to ali those 
who are unable to obtain the syringes, as it is 
both effective and cheap. 
The effect, which the sulphate of copper has 
upon the fungus, is to paralyze the generative func- 
tions of the oogonia, and to thus effectually stop 
the propogation of the oospores and conidia. 
Considering the widespread diffusion of the 
disease, not in these islands only, but also in all 
of the countries along the Mediterranean shores, 
the commission recommends that immediate steps 
should be taken in order that the generation of 
the oospores which are now in course of formation 
may be arrested, and the grape harvest of next 
year saved. The treatment above recommended 
should be at once applied after which, a regular 
and methodical course as follow's should be 
adopted. 
I. As soon as the buds of the vine appear, the 
plants should be treated with the powder consist- 
