26 



The following table, No. IX, gives the composition of the water in 

 the drainage ditches, sampled near the places where the soil samples were 

 taken. 



(At location No. 11 a sample of the drainage water could not be ta 

 ken, as the ditches were dry.) 



All these analyses, with the exception of Nos. 9 and 10, were made 

 by Mr. Shapley, Chemist at Plazuela. 



We have seen before that when a given sample of soil contains not 

 one but several salts simultaneously, the injurious action of these salts' is 

 not directly additive. On the contrary, any salt when present in a soil 

 in mixture with other salts, is less harmful than would be the case were 

 it present by itself. However, when the salts contained in several samples 

 are present in about the same proportions in each one, then the total 

 quantity of salts found in each sample will be representative of the 

 relative amount of injury caused by the salts in that sample. Such is 

 the case in our soils, and therefore, in discussing the results of our 

 analyses, we shall consider the sum of the acid radicles, as given in the 

 above tables. The higher we find the total quantity of salts, the more 

 injury we may expect. 



We shall first try to determine if there is any regularity in the 

 general distribution of the salts over the estates controlled by the Plazuela 

 Sugar Company. With this purpose in view we shall arrange in tabular 

 form the average figures for the total acid radicles of each soil and its 

 corresponding subsoil, as being indicative of the "saltness" of the place, 



