118 



TABLE 2. Duplicate determinations of phosphorus by carbonate fusion. 

 [Water-free basis.] 



In Table 3 will be found duplicate determinations of total phosphorus in soils by 

 the magnesium nitrate digestion. Of these, Nos. 1127, 1202, and 1204 are presumably 

 Texas soils, and the determinations were made by Mr. E. C. Carlyle, of the Texas 

 station. The others are low phosphate soils of western Kentucky and were made as 

 checks in the general work of this laboratory. 



TABLE 3. Duplicate determinations of phosphorus by magnesium nitrate method. 



[Water-free basis.] 



Table 4 shows the modified method to compare very favorably with the regular 

 J. Lawrence Smith method for total potassium, the former method giving in the gen- 

 eral average 0.01 per cent more potassium in both soils. Taking into consideration 

 the fact that the work is done on 1 gram the agreement is as close as could be expected. 

 Referring to the work done by these methods in 1906 and 1907, it will be seen that 

 the results are in the main concordant. 



