506 QUEENSLAND AGRICULTURAL JOURNAL. [1 Juxx, 1898. 
With regard to this treatment, carefully conducted experiments (vid. 
Howard and Marlatt, X.) and lengthy experience in the work of subduing the 
insect under notice in the United States, carried out by them and other 
workers, indicate the following amongst the better methods of procedure :— 
_ The trees after being cut right back should be sprayed with the whale-oil 
soap wash previously described, which must be applied with such force as to 
find an entrance into all the crannies resorted to by the insect. The full results 
following the application of this wash, it is stated, are not usually apparent 
till some weeks have elapsed, and occasionally it may be found necessary to 
make a second application. LL. O. Howard, in summarising the outcome of a 
number of carefully conducted experiments (vid. VIIL., pp. 293-5; and X., 
pp. 108-9), carried out at Washington during the winter 1893-4, states that 
“the only absolutely perfect results which have been reached have been 
attained by using this soap preparation” (and another that is not only costly, 
but very liable to injure the trees to which it is applied). 
Tn California good results have followed the use of a winter spray composed 
of lime, salt, and sulphur prepared as follows:—Ingredients: Unslaked lime, 
40 lb.; sulphur, 20 1b.; stock-salt, 15 1b. ; water, to make 50 gallons. Process 
of manufacture: ‘Place 10 Ib. of lime and 20 Ib. of sulphur in a boiler with 17 
gallons of water, and boil over a brisk fire not less than an hour and a-half, or 
until the sulphur is thoroughly dissolved. (When this takes place the mixture 
will be of an amber colour.) Next, place in a cask 80 1b. of unslaked lime, 
ouring over it enough water to thoroughly slake it; and whilst it is boiling add 
the 15 lb. of salt. When this is dissolved, add to the lime and sulphur and cook 
for an hour longer, when the necessary amount of water to make the 50 gallons 
should be added.’—Dr. J. B. Smith, XT., p. 551-552. This application is 
liable to be washed off by rain before it has fully served its purpose; it therefore 
gives its best results when used in a dry climate. 
‘The composition of other somewhat similar Californian washes as well as 
Oregon modifications of them are given also by the last-mentioned authority. 
They, however, are, like it, not only troublesome to make, but they are also 
exceptionally severe upon the hands of the operator and upon ordinary spraying 
appliances. 
Moreover, according to L. O. Howard and C. L. Marlatt (¢f op. cit.), when 
these washes were experimented with under test conditions at Washington, the 
results following their use were entirely unfayourable. In explanation of this, 
however, it has been suggested that the difference between the Pacific and 
Eastern States, as regards climate, influences the efficacy of their use. 
Tn some instances good results have followed painting the entire wood, 
also jn winter when the buds are dormant, with (1) a wash composed 
of 3-]}. of commercial potash, 3-Ib. of caustic soda, and five quarts of water, 
or a practically saturated solution of the salts named (C. V. Riley, “ Report of 
Entomologist,” 1893) ; (2), pure kerosene; and (8), a mixture of linseed oil ~ 
and the latter body (three parts of the former to one part of kerosene)—a 
combination favourably reported on by R. Hoggan (zn Ut.) 
The winter treatment may be profitably supplemented by the application 
of summer remedies, notwithstanding the drawback to their employment 
already referred to. These, as recommended by the United States Ento- 
mologist, might consist of standard kerosene emulsion (Riley-Hubbard 
formula), one in ten parts of water; or a whale-oil soap wash of 1 lb. to one 
gallon strength (Howard, IX., page 91.) Either of tkese, however, would 
require to be used at least three times at short intervals. 
From what has been already recorded (V., p. 154, there can also be but little 
doubt (for unsatisfactory results in some instances ¢/: xv., pp-467-8) butthat when 
orchard trees that have become infested with the Pernicious Scale are subjected 
to the action of hydrocyanie acid gas, they will by its use be rendered free 
