CCXxii GENERAL SUMMARY OF SCIENTIFIC AND 



" On the Importance as Plant-food of the Nitrogen of the 

 Soil," which enforce and, in part, explain the fact that the 

 nitrogen of vegetable mould the organic nitrogen of the 

 soil is under certain conditions available as food for 

 plants. 



Storer has also conducted a very interesting and impor- 

 tant series of field experiments on the effects of different 

 fertilizers on a soil which may be taken as . a type of the 

 light soils overlying gravelly drift that are common in New 

 England. Potash proved more efficient than phosphoric 

 acid or nitrogen, thus showing that the land stood most 

 in need of potash. Indeed, in some cases, in this naturally 

 sterile soil, phosphoric acid proved actually injurious to 

 crops. Storer thinks this ill effect is due to the inability of 

 the young seedling to endure excess of phosphoric acid in 

 absence of needful supplies of other plant-food, and suggests 

 as a new reason the higher value of superphosphates, that 

 the soluble phosphoric acid is more uniformly diffused 

 through the soil, so that no hurtful excess can come in con- 

 tact with the roots of the plant. 



A number of cases of poisoning of crops by ammonium 

 sulphocyanate are reported in Europe. This compound 

 sometimes occurs in the ammonia salts which are made at 

 gas-works and used for fertilizers. It is recommended to 

 test all fertilizers which may contain these salts for am- 

 monium sulphocyanate. 



That the subject of fertilizer analysis is receiving in- 

 creased attention in this country is evinced by the reports 

 of the chemists of Boards of Agriculture and of inspectors 

 of fertilizers of various states. The reports of Professor 

 Johnson, of Connecticut, Professor Goessmann, of Massa- 

 chusetts, and of the inspectors of fertilizers of some of the 

 Southern States, contain much timely information, and are 

 exerting a great and salutary influence upon the trade in 

 fertilizers. 



Under the head of Vegetable Physiology, we note some 

 very interesting water-culture experiments, by Fittbogen, 

 on the quantity of nitrogen needful as food for the maxi- 

 mum development of the oat plant, which show the relation 

 between the amount of nitrogen supplied and the yield of 

 straw and seed, and accord with the results of other observa- 



