New YorkK AGRICULTURAL EXPERIMENT STATION. 371 
The results embodied in the preceding table are summarized 
as follows: 
(1) Weight of solution and sediment.— In every case, in- 
creased length of boiling decreases the weight of the completed 
solution and increases the amount of sediment. 
(2) Sulphur as sulphides.— In general, boiling the mixture 
for one hour produces the largest amount of soluble sulphides, 
especially when larger amounts of lime are used. 
(3) Thiosulphate and sulphite sulphur.— Increased length of 
boiling results in the appearance of smaller amounts of thio- 
sulphate in solution. In general, we should expect larger 
amounts of thiosulphate, due to prolonged exposure at boiling 
temperature to the action of atmospheric oxygen. Larger 
amounts of thiosulphate are actually formed but a consider- 
able amount changes into sulphite sulphur and appears in the 
sediment as calcium sulphite along with some free sulphur. It 
is necessary to boil the solution long enough to change the 
thiosulphate first formed into sulphite and free sulphur; the 
free sulphur thus formed is utilized, being redissolved and con- 
verted largely into sulphide sulphur. . Boiling for one hour in 
the presence of sufficient lime appears to be long enough in 
general to reduce thiosulphate to a relatively small amount 
and thus utilize the sulphur more largely as sulphide. 
(4) Lime in solution— The amount of lime in solution ap- 
pears usually to decrease with length of boiling, due to change 
of calcium thiosulphate into insoluble calcium sulphite. 
(5) Free sulphur in sediment.— In general, the amount of 
free sulphur in sediment is greatest when the boiling of the 
mixture is shortest. This is due, as would be expected, to in- 
complete action of lime on sulphur and is noticeably greater 
when the amount of lime used is least. 
(6) Combined sulphur in sediment.— The sulphur in sed1- 
ment, combined largely ag calcium sulphite (CaS,), with small 
amounts of sulphate (CaS,), increases with the length of boil- 
ing. As already pointed out, this comes largely or wholly from 
the change of calcium thiosulphate (CaS,O,) into calcium 
sulphite and free sulphur. 
