EXPERIMENT STATION BULLETINS. 



311 



With two or three exceptions, which are easily explained, there is 

 very little difference between the filtered and unfiltered solutions after 

 standing for several weeks, neither do they vary much from the original 

 solutions. In the first sample, the filtered solution IC, was found to be 

 much weaker than the unfiltered, and this is explained by the fact that 

 the stopper of the bottle containing the solution did not fit tightly, thus 

 allowing it to be more or less exposed to the air. Samples 3B and 4B 

 were found to contain less soluble sulfur than the corresponding filtered 

 solutions, and this is explained by the fact that from each of the barrels 

 in which these solutions were stored portions were removed for use by 

 the Horticultural department thus leaving a large air space over the so- 



