690 Tbansactions of the American Institute. 



kind of crop to be grown, but in the average of instances will approxi- 

 mate to that given for double refined poudrette, viz, : For wheat, rye, 

 oats and barley, from 300 to 400 pounds ; for buckwheat, 200 ; 

 for turnips, twice as much; and for top-dressing on grass lands, 

 from 250 to 400. All ammoniated manures should either be inti- 

 mately mixed with the soil or applied thereto before "or during a rain, 

 in order that the ammonia may be retained and carried down within 

 the reach of the roots ; whereas, if left upon the surface during hot 

 weather, a portion of the ammonia would be dissipated, and the 

 remainder would lie inert, out of the reach of the plants. With 

 reference further to ammoniacal manures, it may be mentioned that 

 inasmuch as they are believed to be the most active in developing 

 the growth of straw and leaves, they should be applied as early as 

 possible ; while the superphosphates, which tend mainly to the devel- 

 opment of the seed or kernel, may, when desired, be applied later in 

 the season. The question is frequently asked, by those unfamiliar 

 ■with the chemistry of manm-es, whether lime or ashes may not be 

 Tnixed with poudrettes and similar products, to advantage. This 

 should never he done^ for the reason that either lime or potash is a 

 stronger alkali than ammonia, and if brought into contact with any of 

 its comj^ounds will nsnrp its place, thus liberating the ammonia, and 

 ■destroying the value of the fertilizer. 



Adulterations of Coivimekcial Manuees. 



The adulteration of artificial fertilizers by dishonest dealers has 

 l)een coexistent with their manufacture and sale from the beginning, 

 and the query is often made if there is no cheap and simple test by 

 which the farmer may ascertain the exact nature of the material he 

 buys, and thus protect himself from imposition. To this there can be 

 but one candid answer. That there is not, and that the only certain 

 and trustworthy test of the probable value of this class of manures 

 consists in a careful analysis by a competent chemist, which will often 

 cost as much or more than a ton of the fertilizer. The manufacturer 

 can afibrd this in order to know and to keep up a standard of his pro- 

 ducts, and the dealer can afibrd it if he suspects the manufacturer ; but 

 the farmer will find the outlay too heavy, and hence his only reliance 

 is upon the integrity and standing of the seller. It is true that the 

 addition of lime to guano, poudrette, etc., will cause the liberation of 

 ammonia, which will indicate the ammonial nature of the substance 

 to the sense of smell, and even afford an approximate idea of the , 



