18 FERTILIZERS. 







posit appears to be inexhaustible in its extent. The gen- 

 eral name given to the potash-bearing mass is carnallite, 

 from the pinkish color which it bears. Most of the prod- 

 ucts marketed are made from the original material of the 

 bed by chemical processes, which, as is common in old 

 countries, are kept well-guarded secrets. It comes to this 

 country in different grades of muriate, sulphate, and kai- 

 nite. 



The chemists tell us that a high grade of muriate of 

 potash contains about 80 per cent of muriate of potash, 

 which is equal to 50 per cent of potassium oxide, or pure 

 potash. A high grade of sulphate contains about 52 per 

 cent of sulphate of potash, which is equal to about 28 per 

 cent of pure potash, and 30 per cent of sulphate of mag- 

 nesia, which is equal to 10 per cent of magnesium oxide. 

 A high grade kainite contains about 30 per cent of sul- 

 phate of potash (equal to about 14 per cent pure 

 potash), 35 per cent of chloride of sodium (which is but 

 another name for common salt), and 10 per cent of sul- 

 phate of magnesia. It generally has also some chloride 

 of magnesia. 



In buying these fertilizers, we farmers are apt to think 

 we are getting more potash than they really contain. For 

 instance, 80 per cent of muriate of potash is apt to be 

 taken as meaning 80 per cent of potash, whereas it means 

 80 per cent of potassium combined with chlorine. The 

 quantity of potassium in the 80 per cent of pure muriate 

 would make 50 per cent of the weight of what we buy in 

 pure potash : and so on of each of them. Of wood ashes, 

 we are told that a certain quantity contains 5 per cent of 

 carbonate of potash. Now, carbonate of potash is not 

 pure potash, but a combination of carbonic acid (a com- 

 pound of carbon and oxygen) and potash ; about two 

 parts of the five being carbonic acid, leaving but three 



