EXPERIMENT STATION BULLETINS. 



385 



interest to note that there was quite a large excess of sulfur used in 

 making up each sample except in the case of No. 4. In No. 4 the 

 formula 50-100-50 was used and since the lime used in this case was 

 96.4% pure calcium oxide the excess of sulfur was small. Sample No. 

 4 was the onl}^ one in which there was not a decrease in the thiosulfate 

 sulfur in the uufiltered solution. 



The second of the above three observations would lead us to con- 

 clude that 'there is no marked advantage to be gained from filtering 

 the solution before storing. The third observation would lead us to 

 conclude that if, as many experimenters maintain, the value of the 

 solution depends upon the amount of sulfide sulfur present, it is better 

 in those cases where an excess of sulfur has been used in making up 

 the solution to allow it to stand in contact with its sediment. 



EFFECT OF RE-HEATING THE SOLUTION BEFORE USING. 



H. L. Fulmer^ of the Ontario Agricultural College advises that the 

 lime sulfur solutions which have been allowed to cool should be re- 

 heated before using. In determining the advantage to be gained in re- 

 heating the samples before using, samples 3, 4, and 8 of the above ex- 

 periment were used. In sample 3 and 8 the excess of sulfur in the 

 sediment was large; in sample 4 the excess of sulfur was small. The 

 analyses corresi)onding to the numbers 3B, 4B, and SB are the same as 

 given under the same numbers in the preceding table and represent the 

 analyses of solutions that have stood for some time in contact with the 

 sediment. The analyses corresponding to the numbers 3D, 4D and 8D 

 are analyses of the same samples that have been re-heated nearly to 

 boiling in contact with the sediment, filtered while hot and analyzed. 



TABLE IX. 



In samples 3 and 4 it Avill l)e noticed that there is a slight increase 

 in the amount of total sulfur in the solution that has been re-heated, 

 practically all the increase being in the sulfide sulfur. In sample 8 there 

 is a slight increase in the thiosulfate sulfur and a corresponding de- 

 crease in tlie sulfide sulfur making the total sulfur in solution about the 

 same as in the solution that has not been heated. From the above table 



1 Bull. 177 Ontario Agr. College. 

 49 



