RECTIFIED PERUVIAN GUANO. 307 



increased to such an extent at times, as to seriously depre- 

 ciate the commercial vahie of the material. On the other 

 hand, not unfrequently, entire cargoes, or parts of them, 

 became damaged by sea-water. Both circumstances worked 

 towards the same end; they furnished, although screening 

 and drying as far as practicable had been resorted to, the 

 trade with inferior qualities of genuine Peruvian guano. To 

 save the reputation of their business, the agents of the Peru- 

 vian Government, in Germany (Messrs. G. D. Mutzenbach & 

 Sons), were induced in 1864, to cease selling these inferior 

 guanos at a general auction to the highest bidder, which had 

 been their previous mode of disposing of them, for it offered 

 unusual cliances for fraudulent practices, and affected thereby 

 seriously their interests. 



These guanos were, henceforth, only to be sold at lower 

 rates, with a full statement of their character, either directly 

 to formers or to those dealers, who had no privilege to sell 

 the genuine Peruvian guano ; they served in the latter case 

 usually as. stock for the manufacture of artificial fertilizers of 

 various descriptions. 



Messrs. Ohlendorff & Co., of Hamburg, who at this sta<re 

 in the history of the guano trade were largely engaged in 

 drying the guanos damaged by sea-Avater, decided to adopt 

 the course recommended to them by Dr. Meyn and other 

 agricultural chemists ; namely, to treat the damaged material 

 with sulphuric acid, and to produce thereby an efficient new 

 fertilizer. 



The results of their experiments were subsequently intro- 

 duced to the farmers of Germany by the name of Ohlendorff ^s 

 soluble Peruvian guano. 



The process of its manufacture, as at first carried out, may 

 be described as follows : the moist Peruvian guano is dried at 

 from 75° to 100° (Centigrade) in suitable stoves, and the 

 dried mass, after grinding and screening, treated, in large 

 cemented brick tanks, with concentrated sulphuric acid 

 {QQt^ B.), taking for every one hundred pounds of Peruvian 

 guano, from twenty to twenty-two pounds of the acid. 



The well-mixed mass was subsequently discharged upon a 

 tight floor to dry ; and after weeks of curing, ground into a 

 fine powder, to allow a uniform distribution within the soil. 



