404 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



reduced them. This injurious action of phosphates Storer 

 has known only on poor soils. To investigate the cause, he 

 " tried a number of experiments in pots with the view of de- 

 termining how large an amount of phosphatic manure may 

 be safely applied to sterile land. From the results obtained 

 it would seem that bone-dust and other phosphates, when 

 present in too large a quantity, may exert an exceedingly 

 hurtful influence upon the development of the plumule, or 

 first sprout that springs from the seed, especially at the time 

 when the young shoot is ceasing to draw nourishment from 

 the seed, and is beginning to live upon matters derived from 

 the soil and air. It appears that the young seedling can not 

 endure the presence of a certain excess of phosphate of lime ; 

 at least when the soil in which it stands is too poor to sup- 

 ply at once all the food the plant may need. 



The superior value of superphosphates is, in general, as- 

 cribed solely to the fact that, being in the soluble form, 

 their phosphoric acid is more readily imbibed by the roots 

 of the plant, and they thus become immediately available as 

 plant-food. In view of the fact that contact of too much 

 phosphate w T ith the seed may cause the young plant to per- 

 ish almost at its birth, Professor Storer suggests that the 

 superphosjmate may be better, because safer. The soluble 

 phosphate will be more uniformly diffused through the soil, 

 so that no hurtful excess may in any place come in contact 

 with the roots. 





