105 



Now, to determine the class of any soil does 

 not require any very profound knowledge of analy- 

 tical chemistry. A few readily ascertained facts 

 suffice, and the following directions will be useful 

 to those unable to consult a trained chemist : 



1. Take 100 or 1,000 grains of a soil, after 

 well drying it in an oil-bath -at 250 F., and heat 

 it to redness in a platinum crucible, keep up the 

 heat for half-an-hour, stirring the mass occasionally. 

 Cool, and weigh. The loss of weight is Humus. 



2. Digest what remains in the crucible in a phial 

 with cold, diluted muriatic acid (| oz. acid to 10 oz. 

 water to 100 grains soil) for about an hour, shaking 

 it from time to time. Filter through a weighed fil- 

 ter, and wash with pure water until the liquid pass- 

 ing through ceases to be sour. Dry the whole at 

 250 F. ; weigh, and deduct the weight of the filter. 

 The loss of weight represents the amount of Lime. 



3. The contents of the filter are now carefully 

 removed into a tall glass cylinder, and the impalpable 

 matter separated from the sand and coarser particles 

 by repeated washing with water. Stir well, let subside 

 for a minute, and pour off the supernatant liquid. 

 The impalpable matter thus separated represents the 

 clay. Collect in a filter, dry as before, and weigh. 



4. The remainder is Sand. 



It must be understood that the results obtained 

 by the above method will be only approximate, but 

 still reliable enough for the purposes of classification. 



n 



