204 



Analyses of Ashes of Plants, 













45 lbs. 



21 lbs. 



39 lbs. 



Siilnhiirif anr] 



. 50 . 



22 









21 „ 



197 „ 



Magnesia . 



. 14 „ 



22 „ 



29 „ 



Potash 



. 140 „ 



133 „ 



134 „ 



Soda .... 



. 33 „ 



70 „ 



103 „ 



Chloride of sodium 



. 57 „ 



160 „ 



85 „ 



Now it is to be observed that, in the present favourite method 

 of manuring with bones dissolved in sulphuric acid, we make 

 provision for the three first substances. Recent bones contain, 

 in round numbers, half their weight of phosphate of lime, which 

 phosphate of lime consists of nearly equal weights of phosphoric 

 acid and lime. Bones, then, contain one-fourth of their weight 

 of phosphoric acid. To supply the 45 lbs. required by a crop of 

 turnips we must not employ less than 2 cwt. of bones, leaving one- 

 eighth of this quantity for loss. If the bones be dissolved in sul- 

 phuric acid (one-half their weight being employed), abundance 

 of this latter substance will be introduced into the soil ; and the 

 lime of the bones, although not sufficient for the crop, will per- 

 haps be an adequate addition, considering the prevalence of this 

 earth in most cultivated soils. 



But when bones and sulphuric acid are alone used, where is 

 the plant to obtain its magnesia and its alkalies? Certainly not 

 from the bones, for although soda and magnesia do exist in bones, 

 it is in very small quantity. Following out our supposition of a 

 barren soil, we must add about 2 cwt. of pearl-ash, three-quar- 

 ters of a cwt. of Epsom salts, and (trusting to common salt to 

 supply soda) 1 cwt. of common salt. 



These are the quantities required for a crop of turnips. A 

 crop of beet will require only half the bones and acid, the same 

 quantity of pearl-ash as turnips, and twice as much common salt 

 and Epsom salts. Twenty tons of carrots and their leaves will 

 require the same quantity of bones and acid and pearl-ash, and 

 twice as much Epsom salts and common salt as turnips. 



Now, it is to be understood that we are speaking of the addi- 

 tions that must be made to soils having no available resources of 

 their own. It is anything but our intention to recommend such 

 methods as these, which would entail a ccmsiderable expense, 

 and would in many cases be needless. We, however, think that 

 sufficient attention has not been paid to the constitution of the 

 manures used in the turnip culture. 



It is to be remembered that a turnip-soil is not that which 

 should supply the plant most freely with potash or soda, for these 

 alkalies most abound in the stiff clays which are not suitable to 

 the turnip ; it is to no purpose that we feed a plant liberally with 



