420 EARLIEST OPINIONS OP SOILS. 



the strata of inarl through which they pass; and which being in- 

 timately mixed with sand, clay, and vegetable matter, is sufficient 

 to form the finest and deepest soil. All the rich low grounds 

 which I have had an opportunity of observing, have marl on some 

 of the- streams which fall into them, and I have not heard of any 

 on those few which are poor. Not a solitary instance of shells 

 being found in poor land of any description has come to my 

 knowledge. 



" If these premises are correct, no other conclusion can be drawn 

 from them but that a proportion of calcareous earth gives to soil a 

 capacity for improvement which it has not without ; and it also 

 follows, that by an application of shell marl, the worst land would 

 be enabled to digest and retain that food, which has hitherto been 

 of little or no advantage. 



<l The property of fixing manures is not more important in marl, 

 than that of destroying acids. The unproductiveness of our lauds 

 arises not so much from the absence of food as the presence of 

 poison. We are so much accustomed to see a luxuriant and rapid 

 growth of pines cover land on which no crop can thrive, that we 

 cannot readily see the impropriety of calling such a soil absolutely 

 barren. 



" From the circumstance of this soil being so congenial to the 

 growth of pine and sorrel (both of which are acid plants), it seems 

 probable that it abounds in acidity, or acid combinations, which 

 (although destructive to all valuable crops) are their food while 

 living, and product when dead. The most common forest trees are 

 furnishing the earth with poison as liberally as food, while it depends 

 entirely on the presence of the antidote, whether one or the other 

 takes effect. I have observed a very luxuriant growth of sorrel on 

 land too poor to support vegetables of any kind, from green pine 

 brush having been buried to stop gullies ; and it is well known how 

 much land on which pines have rotted is infested with this perni- 

 cious plant. Marl will immediately neutralize the acid, and this 

 noxious principle being removed, the land will then for the first 

 time yield according to its actual capacity. Sorrel will no longer 

 be troublesome; arid, by a very heavy covering, I have known a 

 spot rendered incapable of producing it, although the adjoining 

 land was thickly set to the edge. Pines do not thrive on shelly 

 land, whether fertile or exhausted. To this cause I attribute the 

 great and immediate benefit I derived from marl on new ground. 

 The acid produced by the pine leaves is destroyed, and the soil is 

 capable of supporting much heavier crops, without being (as yet) 

 at all richer than it was/' * * * * 



Communication to Prince George Agricultural Society, 1818. 



Before proceeding to state later experiments; and general prac- 



