COMMERCIAL MANURES. 215 



Superphosphates. — Several of our agricultural friends have written to us, asking 

 which lind o{ "superphosphate" we would recommend them to purchase. Certainly 

 there ought to be only one kind of superphosphate, and that a genuine superphosphate 

 of lime, containing at least ten per cent, of soluble phosphoric acid, and an equal quan- 

 tity of insoluble, in addition to the phosphate of lime. AYe do not know of any brand 

 we can recommend as being properly manufactured, genuine superphosphate of lime. 

 If there is any in the market, we have not been able to find it, and we have searched 

 diligently. As the inquiries are presented, we can make no answer. If the questions 

 should assume another form — " What compounds, composts, or mixtures, such as are 

 put up in barrels, and .labelled 'superphosphate,' we would recommend," we should 

 still be unable to reply; as we have found these mixtures to vary so exceedingly in 

 fertilizing value, little reliance can be placed upon them. In color, some are quite 

 dark; others gray, or light yellow. In odor, one is like fish offal, another like carrion; 

 others have a kind of sulphurous smell. The color is due to an admixture of charcoal, 

 or bone-coal, or sugar refiners' waste, in varying quantities. As regards the origin of 

 the differing odors, we suppose, when the manufacturers run short of cheap fish pomace, 

 they substitute dead cats and dogs, or other decomposing flesh. As a rule, that "super- 

 phosphate " which has the darkest color and the most abominable smell, sells the best, 

 as it is regarded the " strongest." Manufacturers under.stand this, and take advantage 

 of it. True, genuine " superphosphate " is almost colorlesa, and has but a faint acid 

 smell, cot in the least unpleasant. To manufacture such, all that is required is to dis- 

 solve fine bone-dust in oil of vitriol, 150 pounds of the former to 80 of the latter, with 

 the addition of sufficient water to form an intimate and perfect mixture. In the home 

 manufacture of this fertilizer, 60 pounds of acid, with 150 of fine bone may be em- 

 ployed, as it is better to avoid the risk of any free acid remaining in the mixture after 

 the action is over. AVe have given, in a former number of the Journal, full directions 

 for making superphosphate upon the farm. Farmers can and should make their own 

 superphosphate. 



I have not the honor of a personal acquaintance with the writer 

 of this article, but it is due to say, that Dr. Nichols is understood 

 to enjoy the reputation of being a very estimable gentleman, a 

 practical and scientific chemist, and farmer also, and occupies a 

 position at the head of an establishment for the manufacture 

 and sale of chemical preparations, chiefly medicinal. It is also 

 proper to say that the Journal in question has been the vehicle of 

 much information and advice which was accurate, sensible, and 

 effective for good. 



I quote this editorial partly because it utters no uncertain 

 sound, partly because its authorship secures its acceptance by 

 many who would scrutinize as loud a statement if made by one 

 possessing less reputation as both a chemist and an agriculturist, 

 but chiefly because, appearing in a journal claiming twenty-five 

 thousand readers, and having been extensively copied into agri- 

 cultural and other newspapers, has obtained a very wide circulation. 

 Copies were sent me last spring from various parties, with the 

 inquiry what answer I had to make. But I replied to none. I 



