3 
a few days without rain can not safely be counted on. So poor were 
the results, in fact, that the writer felt inclined to doubt the effective- 
ness of these washes even in California. But subsequent trips to Cali- 
fornia and careful investigation of conditions there, demonstrated to his 
complete satisfaction that the effectiveness of these washes on the Pacific 
coast had not been overstated. 
CALIFORNIA WASH AGAIN TESTED. 
The confirmation thus gained of the value of the California wash as 
an insecticide led the writer in the spring of 1900 to again institute 
some experiments with it against the San Jose scale and the Diaspis. 
These experiments are recorded in detail in Bulletin 30 (new series) of 
this Office, pp. 33-39. They include also parallel experiments with 
kerosene emulsified in the Bordeaux mixture and kerosene-lime emul- 
sion, both suggested by Professor Galloway; and also a test with white- 
wash made at the suggestion of Doctor Howard. A special steam plant 
was prepared, so that the lime, sulphur, and salt wash could be made 
after the most approved methods and thoroughly boiled. An account 
of these experiments, so far as they apply to the lime, sulphur, and salt 
wash, is transcribed below from the publication cited. The report of 
the chemist on this mixture is of especial value and seems to confirm 
the view previously expressed on the relative effect of a moist and of a 
dry climate on the behavior of the wash. 
RECORDS OF EXPERIMENTS IN 1900.1 
Lime, sulphur, and salt wash.—A mixture of this substance was prepared, 
differing slightly from the formula given in Farmers’ Bulletin No. 19 in that the 
amount of lime was somewhat reduced, namely, from 40 to 30 pounds. This 
reduction in the amount of lime was made simply because in the ordinary for- 
mula the lime is very greatly in excess and remains as a pure lime sediment in 
the wash and has to be kept in suspension by agitation. Even as thus reduced 
there is still a considerable excess of lime. ‘The formula followed was: 
WAT) ERE ee ae soe pounds__ 30 
all) id es Do ee ee 2002 == 20 
Set) te cee TU Ee AL Le doze Lb 
\iV ler = oe 2 es ae SN Sy es eee Se SEM ovate S50) 
The mixture was steam boiled all together in barrels about four hours and 
applied March 23 and repeated March 24. The hot liquid was taken immedi- 
ately from the barrels at almost a boiling temperature and sprayed at once on 
the trees. A series of experiments was also made with the preparation of this 
wash on a smaller scale, following practically the same formula. The products 
obtained were submitted to the Chemist of this Department for analysis, and the 
assistant chemist charged with the work was especially advised just what fea- 
tures were supposed to be desirable and what points the analysis should bring 
out. The result of this analysis, made by Mr. J. K. Haywood, of the Bureau of 
Chemistry, as reported by Dr. H. W. Wiley, Chief Chemist, is given in a foot- 
' Bul. 30 (new series), Div. of Entomology, pp. 34-37. 
