EXPERIMENT STATION". 19 



In case of a fine, imiform and moist or coherent article, a butter- 

 tryer or a tin tube, like a clipper handle, put well down into the 

 packages in a good number of places will give a fair sample with 

 great ease. With dry, coarse articles, such as ground bone, there 

 is likely to be a separation of coarse and fine parts on handling. 

 Moist articles put up in bags or common barrels may become 

 dry on the outside. It is in these cases absolutely necessary to 

 mix thoroughly the coarse and fine, the dry and the moist portions 

 before sampling. Otherwise the analysis will certainly misrepre- 

 sent the article whose value it is intended to fix. 



The quantity sent should not be too small. When the material 

 is fine and uniform, and has been carefully sampled, a pint may be 

 enough, but otherwise and especially in the case of ground bone, 

 which must be mechanically analyzed, the sample should not be 

 less than one quart. 



It is also important that samples for analysis should be taken at 

 the time when the fertilizer is purchased, and if they cannot be at 

 once dispatched to the Station, they should be so preserved as to 

 sufier no change. Moist fish, blood or cotton seed will soon 

 decompose and lose ammonia, if bottled and kept in a warm place. 

 Superphosphates containing much nitrogen will sufier reversion 

 of their soluble phosphoric acid under similar circumstances. 

 Most of the moist fertilizers will lose water unless tightly bottled, 

 but some of the grades of potash salts will gather moisture from 

 the air and become a slumpy mass if not thoroughly protected. 



These changes in the composition of a sample not suitably pre- 

 served, must invalidate any conchisions from its analysis, and 

 work serious injustice either to the manufacturer or to the con- 

 sumer. 



It doubtless often happens that a purchaser on laying in a stock 

 of fertilizers, decides that he will not then trouble the Station to 

 analyze the goods he has obtained, but will set aside samples 

 which he can send for examination in case the crops report 

 adversely as to their quality. It is always better to send all sam- 

 ples at once to the Station where they can be directly analyzed or 

 so prepared that they shall keep without chemical change. 



With the Instructions for Sampling, the Station furnishes a 

 blank Form for Description of Samples, a copy of which is here 

 given. 



