.MA.NTKK. YIKLD AM) S( LI K I. K SA1.TS IX SOILS. 



40 



Mean amounts of water-soluble salts recovered from 6 soil types 

 under different treatments. 



From this table it is seen that lime has increased each ingre- 

 dient determined, except chlorine and silica. The manure alone 

 has increased all ingredients except silica ; the nitric acid 40 

 parts per million, phosphoric acid 1.63 parts, the sulphates 

 15.6 parts, and the chlorine 8.76 parts; while the lime and the 

 manure combined have produced much the largest gain of each 

 of the first three ingredients of the table. 



INFLUENCE or MANURE UPON THE WATER-SOLUBLE SALTS RE- 

 COVERED FROM PLANTS. 



At the same time samples of soil were taken, others from the 

 corn and potatoes growing upon the soils, were collected and 

 examined for the water-soluble salts which could be recovered 

 from them, the object being to ascertain whether the differences 

 observed in the soil were also reflected in the sap of the crops 

 themselves. In procuring the solutions for examination, the 

 plant samples were first cut fine and dried water-free at 100 O, 

 when a weighed quantity of the crisp material was rubbed 

 down in a mortar and after this a small quantity of distilled 

 water added so as to form a thick paste. In this condition the 

 material was crushed in the mortar by nibbing during from 

 3 to 5 minutes; after which enough more distilled water was 

 added to equal 100 times the dry weight of the sample crushed. 

 In this condition, carbon black was added and the solution al- 

 lowed to stand 20 to 30 minutes to be decolorized. 



In the following table there are given the amounts of water- 

 soluble salts which were recovered from corn and potatoes grow- 

 ing upon the sub-plots to which 15 tons of manure were added 

 and upoil those to which nothing had been applied: 



