6 Farmers’ Bulletin 1285. 
concentrate of lower density. The high-test concentrate will also re- 
quire less storage space, which is something of an item if large quan- 
tities of spray are needed. 
Formula 2. 
Stone’ ime si =a. 2 ee A ae ee ee eo 2 pounds__ 50 
Sulphur<(commercial, round!) A=. See eS CG. 100 
Water toumake finished product. eee ees gallons. 50 
This formula is perhaps the most popular among those who make 
their own solution on the farm, since by its use a reasonably high-test 
concentrate can be made and, at the same time, the proportion of resi- 
due or sediment is not unduly large. In cooking experiments with 
this formula, the Bureau of Entomology has produced solutions test- 
ing from 27° to 28° Baumé. 
Formula 8. 
Stone slimes le> Seas et Se eee ee pounds__ 50 
Sulphur i(commercial serount)) 222222 eee do____ 100 
Water to make finished product-__--=_-----_-___-__- gallons__ 65 
In this formula it will be noted that considerably more water is 
used, resulting in a less dense finished product. With good materials, 
however, the resulting concentrate should test from 23° to 24° 
Baumé. The proportion of sediment is less in this than in Formulas 
1 and 2; in other words, a larger proportion of the lime and sulphur 
go into solution, due to the more complete utilization of the raw 
materials. 
PREPARATION OF LIME-SULPHUR CONCENTRATE. 
SOURCES OF HEAT. 
As is noted elsewhere, lime-sulphur may be cooked over a wood 
fire in open vessels, such as an iron caldron or kettle, or it may be 
made by the use of live steam or steam in closed coils. The method 
of preparation is essentially the same regardless of the source of 
heat, although if the cooking is done over a fire or by means of closed 
steam coils, it will be necessary to add extra water to replace that 
which is lost through evaporation. In the case of live steam no extra 
water will be required since there is usually sufficient condensation 
of the steam during the boiling process to equal the water lost 
through evaporation. 
AGITATION. 
During the course of the cooking it is essential to keep the mate- 
rials well stirred. With small cookers this is usually accomplished 
by the use of a wooden paddle, while in large plants the stirring is 
usually done by a mechanical agitator operated by power from a 
gasoline or steam engine. It is very important to agitate thoroughly, 
especially during the early stages of the cooking and while the con- 
centrate is being drawn from the cooking tank, to provide an even 
distribution of the sediment. Agitation is also sometimes secured 
by the sissuance of live-steam from perforated steam pipes in the 
bottom of the cooker (Fig, 14). 
