188 GUANO. 



the thinking farmer will readily perceive that it must 

 be very judicious to add some guano to hone-dust^ in 

 order that it may call forth even in the first year the 

 most abundant produce. The same is true of oil- 

 cake also. 



For a thorough manuring, the average reckoning 

 is 4 cwt. of guano to the Saxon acre, or a full 2 cwt. 

 to the Prussian Morgen.* Yet this amount, accord- 

 ing to climate and soil, more particularly in moun- 

 tainous districts, is frequently exceeded ; whilst, on 

 the contrary, a less quantity may be sufficient where 

 climate and soil are peculiarly favorable. 



On the mode of application t the following remarks 



* Literally, as much land as a man can plough in a morning ; — 

 about an English acre. 



t It would not be proper to pass over this mode of preparation 

 without some further notice. 



If a glass rod moistened with muriatic acid be held an inch distant 

 from the surface of a saucerful of Peruvian guano just taken from 

 the bag in which it is imported, a white cloud will be immediately 

 perceived. This is formed by the union of the ammonia rising up 

 and evaporating from the guano with the fumes of the muriatic acid, 

 rendering it manifest that ammonia escapes from guano very readily 

 at the usual temperature of the atmosphere, — of course more abun- 

 dantly in hot than in cold weather. Hence it is evident, that 

 the exposure during the pounding and frequent sifting here recom- 

 mended must be very injurious to the guano, and cause the loss of 

 much of its most valuable ingredient. 



It is much preferable to start the bags on the barn-yard floor, and, 

 after spreading out the guano an inch thick, quickly to cover it with 

 powdered charcoal or fine burnt bone-black, the refuse of sugar re- 

 fineries, or with dry gypsum, or with clay which has been rendered 

 friable by exposure to frost and then broken up and dried moderately, 



