May 5, 1891. 
303 
spraying than the apple, here the reverse is the case. We find 
that, while we do not advise more than 1 oz. of Paris Green in 
20 gallons of water for apple leafage, the plum leafage will usually 
bear a mixture of 1 oz. in 10 gallons. This strengtli, Dr. Liiitner 
writes me, would, in the United States, "bring every leaf oti" the 
plums;" but whether the difference is from climatic influence or 
from difference in kind of plum we have not yet made out. 
We are continuing to find the benefit of last year's treatment. 
I have reports, from various places where the Paris Green spraying 
was used on a large scale, of winter-motii caterpillars (up to date of 
report) being comparatively absent, whilst over a district where (so 
far as I am aware) little or nothing was done in this way I have 
report of the caterpillars appearing in large numbers. In all my 
communications I have been careful to point out that the experi- 
ments were simply directed to checking tlie ravages of moth cater- 
pillars, or insects which bite and swallow the leafage, and (on the 
face of the thing) that the treatment did not appear likely to get 
rid of the kinds of infestations which, like aphides, feed by piercing 
down through the outer tissues and drawing up sap from below. 
Nevertheless, I have a trustwortliy instance sent me in which aphis 
attack was cleared by this spraying, so that, though I would not on 
any account advise its trial on hops, it may be worth while to 
experiment more extensively. 
A great improvement has been made in the manufacture of 
Paris Green by grinding it much finer, consequently on which it does 
not deposit so much as before when mixed with water ; also it can 
be procured damp (as a paste), by which means much of the difficulty 
of mixing the dry powder, and inconveniences from the powder flying 
about in mixing, are avoided. 
Amongst other insecticides, I am giving attention to a mixture 
of soft soap and sulphur, made very nearly on a recipe which has 
been found serviceable in South Australia, and recommended by the 
late Mr. Frazer Crawford (the Government Inspector under the 
Vine, Fruit, and Vegetables Protection Act) in his report, printed 
by direction of the Hon. the Commissioner of the Crown Lands. 
This Australian mixture has been found especially serviceable 
against such attacks as aphis and mildew together, with red spider, 
gall mites, (kc, and likewise against moth caterpillars harbouring in 
bark. I have so very often to recommend the use of soft soap and 
sulphur washes as a preventive for insect attacks of various kinds, 
that, if this mixture answers as well on continued experiment as 
seems likely at present, it may save much trouble to be able to pur- 
chase it. 
Inquiry has been sent me, and also I have been in correspon- 
dence with firms in various parts of the country, as to the desirable- 
ness of issuing a mixture (or emulsion, as it is called) of soft soap 
and Paris Green. I do not advocate this, partly because, so far as I 
am aware, we have no precedents on acknowledged authority as to 
the effects of the mixture according to any given recipe ; partly be- 
cause, the strength of Paris Green in the mixture being possibly 
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