4 Farmers’ Bulletin 1285. 
Different limes behave differently with water, and hence it is often 
advisable to test a sample before proceeding with the actual cooking 
operation. This will enable one to ascertain the character of the 
lime, whether it is quick, medium, or slow in slaking. Limes have 
been classified by the American Society for Testing Materials as (a) 
quick-slaking, (6) medium-slaking, and (c) slow-slaking, and it 
gives the following method for allocating a particular lot: Two or 
three lumps about the size of a man’s fist should be put into a bucket 
and enough water added barely to cover the lime. If slaking begins 
in less than 5 minutes the lime is quick-slaking; in from 5 to 30 
minutes, medium-slaking ; and after 30 minutes, slow-slaking. Slak- 
ing is considered to have begun when pieces split off from the lumps 
or when the lumps begin to crumble. Quick-slaking lime is much 
to be preferred, since by its use time is saved and there is likewise a 
greater concentration of heat which aids in the cooking. The use of 
hot water ia slaking the lime, as advocated in this bulletin, will 
greatly accelerate the action. With slow-slaking lime care should 
be taken not to use too much water at the start in order to avoid the 
possibility of drowning the ime. With this type the lime should be 
placed in a cooker and just enough hot water added to moisten it 
until there is evidence of slaking, after which additional hot water 
should be added cautiously from time to time to maintain the action 
and, at the same time, prevent the mass from burning dry. Medium- 
slaking lime should be treated in a similar way except that more 
water may be added without undue danger of drowning the material. 
When quick-slaking hme is employed the ime may be added to the 
hot water, a sufficient quantity of the latter being used to cover the 
lime. Duriag the slaking care should be taken to have a ready supply 
of additional water on hand to prevent burning. 
If preferred high-grade hydrated lime may be substituted for the 
stone lime, but it will be necessary to use about one-third more of 
this by weight than is given in the formulas for stone lime. <Air- 
slaked lime should never be used, since this has absorbed carbon 
dioxid (CO,) from the air and has thus partly reverted to the 
original rock or limestone, calcium carbonate (CaCO,). 
SULPHUR. 
Sulphur has long been recognized as a useful element, and was 
early employed for medicinal purposes by the ancient Greeks and 
Romans. At the present time sulphur and its compounds are widely 
used against insects and plant diseases. It is found upon the market 
as stick sulphur or brimstone, flowers of sulphur, and commercial 
ground sulphur, the latter also being known as flour of sulphur. 
The flowers of sulphur is produced by heating crude sulphur or 
brimstone until it vaporizes. The vapor is then passed into a cooling 
chamber, where it is condensed and deposited as a very fine powder 
on the walls. The commercial, ground material is cheaper than the 
flowers of sulphur, and if finely pulverized is equally as satisfactory 
in all respects for the manufacture of lime-sulphur concentrates. 
It should be about 98 to 99 per cent pure, and this grade is readily 
obtainable. 
