38 THE COMMERCIAL AND AGRICULTURAL 



is technically called, salt-cake, gypsum, and sand constitute the 

 chief ingredients of this manure, which professes to be superior 

 in efficacy to the best Peruvian guano. 



It will strike you that the second sample contains a very much 

 larger amount of gypsum, and is much drier than the first 

 sample. When first brought out the manure was found too wet, 

 and therefore was objected to by many farmers, who in general 

 like a manure that runs easily through the drill. To remedy this 

 defect the ingenious proprietor of the economical manure intro- 

 duced into its composition a large quantity of gypsum, a cheap 

 material, which answers exceedingly well the purpose of drying 

 up moist substances. 



In this dry condition the economical manure is now generally 

 sold, but its composition is by no means constant, for the pro- 

 prietor has no manufactory of his own, and gets his manure made 

 as best he can. It is made in various parts of the kingdom, 

 generally in localities where chemical manufactories abound, as 

 in the neighbourhood of Liverpool, Bristol, Glasgow, Newcastle, 

 and London. 



By paying a handsome profit to the chemical manufacturers, who 

 in many instances are but too glad to dispose of their refuse mate- 

 rials, the proprietor of the British Economical Manure engages 

 the interests of the manufacturers, and by giving a commission 

 of I/, to 21. for the sale of every ton of this manure he secures 

 agents in all parts of England to dispose of the all but worth- 

 less stuff. 



In the next place, let me point out to you in the subjoined 

 diagram the composition of two manures, one of which is called 

 Mexican guano, and the other professes to be the very essence of 

 Peruvian guano : 



GUANO (so called). 



Mexican. Essence of. 



Water 5'33 8'28 



Organic Matter .. 3'52 13'11 



Oxide of Iron and Alumina 

 Phosphate of Lime 

 Sulphate of Lime (Gypsum) 



3-59 



18-10 2-35 



15-17 



6975 8-00 



Carbonate (Chalk) 

 Chloride of Sodium (common Salt) . . 1-75 15-80 



Insoluble Silicious Matter (Sand, &c.) .. .. 34-29 



Magnesia 1-35 



Loss 



100-50 



Containing Nitrogen 19 52 



Equal to Ammonia 23 64 



Large quantities of this so-called Mexican guano were sold not 

 long ago at a high price, notwithstanding its inferior composition. 



