10 AGRICULTURAL ANALYSIS 



the complete mixture of many substances which are soluble and 

 which are of such a nature that they can not be readily ground is 

 best effected by dissolving them in water or some other satisfac- 

 tory solvent, mixing the solution and taking an aliquot part there- 

 of, as above suggested. 



If liquids have solids in suspension it is often necessary to thor- 

 oughly mix them in order that the sample may contain its pro- 

 portionate part of the solid matters. Milk may be sufficiently 

 mixed by pouring several times from one receptacle to another 

 before the sample is removed. Carbonated liquids may be with- 

 drawn from the casks or bottles in which they are held by means 

 of a spiggot with a stop-cock. In the case of viscous substances 

 a large spatula, cheese-knife or cheese-sampler may be con- 

 veniently employed. For instance, this method of sampling may 

 be practised with a substance like massecuite. In case the degree 

 of fluidity is too great to admit of such a method of sampling, a 

 slotted tube may be use'd which is inserted in the semi-liquid mass 

 until filled and then withdrawn and its contents removed for the 

 sample. Sirups and molasses in which the sugar has been par- 

 tially crystallized offer unusual difficulties in sampling, owing to 

 the great difficulty of breaking up the crystals and mixing them 

 uniformly with the liquid portions. In such cases it is better to 

 dissolve the crystals if possible by gentle heating and stirring of 

 the products, or even the addition of a known amount of water 

 until the whole of the crystallized portions are dissolved. 



There are some plastic materials which it is almost impossible 

 to sample in a uniform way. In these cases it may be found neces- 

 sary to subdivide the material by cutting a selected and occasional 

 piece representing, as nearly as possible, the whole material. 

 Materials like street sweepings and garbage may be sampled 

 when they are loaded or unloaded by taking an occasional shovel- 

 ful and throwing it off to itself, until a carload or other large 

 quantity has thus been sampled. These materials which are re- 

 moved may then be thoroughly mixed together and resampled in 

 the same way. 



Sugar-cane and sugar-beets may be sampled by taking at ran- 

 dom every tenth or hundredth beet or cane. The same is true 



