Lime-Sulphur Concentrate. 5 
CHEMICAL REACTIONS IN THE MAKING OF LIME- 
SULPHUR CONCENTRATE. 
In making lime-sulphur concentrate the first step is to slake the . 
lime (CaO) with water. The union of lime and water produces in- 
tense heat and results in the formation of calcium hydroxid 
(Ca(OH),). The sulphur is next added, as is also more water, and 
the entire mass is then thoroughly boiled and agitated until the lime 
and sulphur have gone into solution. In the course of the boiling 
several chemical compounds are formed, the more important being 
ealcilum pentasulphid (CaS,) and calcium tetrasulphid (Cas,), 
both of which are soluble and are regarded as the most valuable of 
the lime-sulphur compounds for spray purposes. Another soluble 
compound, calcium thiosulphate (CaS,O,) is also formed, although 
it is more or less decomposed into free sulphur (S) and calcium 
sulphite (CaSO,). The latter is insoluble and constitutes the major 
part of the coarse sediment. As previously mentioned, the magne- 
sium that may be present in the lime forms insoluble compounds, 
thereby increasing the amount of sediment or “ sludge.” 
FORMULAS FOR MAKING LIME-SULPHUR CONCEN- 
TRATE. 
In selecting a formula for the making of lime-sulphur concentrate 
the orchardist will naturally desire to use the one that will produce 
the best results at the minimum cost. Although it is impossible in 
the present bulletin to recommend a formula that will best meet the 
requirements of the individual or community plant, it is hoped that 
the suggestions given herein will be of value in this connection. 
Chemical and field tests have shown that hme and sulphur when 
boiled in the proper amount of water will go into solution best in 
the proportion of 1 part of the former to from 2 to 2} parts of the 
latter, provided the chemicals are pure. In most formulas the lime 
and sulphur are used in the foregoing proportions. Three formulas 
extensively and successfully used at the present time are here given 
along with the chief advantages and disadvantages of each. 
Formula 1. 
Stones lim Gyan Ss 2 a. _. > ee ee 2 ee be pounds__ 80 
Sulphur (commercial ground ) == =a 2s ee dol — 160 
Water to make finished produ ctl — = = ae gallons__ 50 
Owing to the relatively large amount of lime and sulphur in com- 
parison with the volume of the finished product, the use of this 
formula results in a highly concentrated material testing 32° to 34° 
Baumé. On account of the comparatively small amount of water 
used, the principal disadvantage of this formula is that there will 
be some waste of materials by the formation of insoluble compounds, 
such as calcium sulphite (CaSO,) or uncombined lime and sulphur. 
If, however, the raw materials are not too expensive, then this loss is 
not serious, since the cost of labor and fuel in producing a high-test 
concentrate is no more than in making a product of lower density. 
By referring to the table of dilutions (p. 11): it will be noted that the 
high-test concentrate will make more diluted spray solution than a 
