384 REPoORtT OF THE CHEMIST OF THE 
(3) Sulphur in form of thiosulphates.—The amount of thio- 
sulphate sulphur, which is present mainly as calcium thiosul- 
phate (Ca,S8,O,), varies in the commercial preparations under 
consideration from 0.69 to 2.26 per ct. It has already been 
pointed out (p. 358) that thiosulphate sulphur is usually 
formed at the expense of the sulphides, so that, in general, a 
high thiosulphate percentage is accompanied by a compara- 
tively low sulphide percentage. The high amount of thiosul- 
phate sulphur in sample K is probably due to incomplete boil- 
ing in making the preparation. 
(4) Insoluble sulphur.—in samples E—G, free sulphur is pres- 
ent in amounts ranging from 0.10 to 1.52 per ct., and sulphite 
sulphur (mixed with small amounts of sulphate), in amounts 
varying from 1.30 to 3.24 per ct. 
(5) Calcium in sulphide compounds.—The amount of cal- 
cium combined with sulphide sulphur varies from 4.42 to 7.21 
per ct., running quite parallel in amount to the sulphide 
sulphur. 
(6) Calcium-sulphur ratio—The amount of sulphide sul- 
phur in proportion to calcium in sulphide combination is fairly 
uniform, quite independent of other variations. This indicates 
that the sulphide sulphur is in the form of calcium pentassul- 
phide (CaS,) and tetrasulphide (CaS,). These relations have 
been quite fully discussed on p. 369. 
(7) Comparison of commercial and home-made preparations. 
-—If we compare commercial and home-made _ lime-sulphur 
preparations, it is noticeable that the commercial preparations 
are Somewhat more concentrated. Home-made preparations 
may contain 22 to 23 per ct. of combined sulphur in solution 
but rarely more, so far as our observations go. The best com- 
mercial preparations for the most part contain 24 per ct. and 
more of soluble sulphur in combined form. This greater con- 
centration is caused by use of less water or by removal of some 
of the water from the liquid portion by evaporation. 
