THE GARDENER. 



15 



permit moisture to penetrate without difficulty through 

 it, nor part with it as other soils will ; it is therefore cold 

 in winter and hard in dry weather, bursting into fissures, 

 so as to cause injury to the plants, whose roots become, 

 in consequence, affected by wind and drought ; in that 

 state it is impenetrable to the tender fibres. Inter- 

 mixture of sand and other loosening substances, with 

 abundance of manure, and thorough draining, will 

 gi-eatly alter the nature of this soil ; but it will never 

 become good for a garden. Yet argil (or clay) is 

 sometimes combined with so much sand, as to form 

 an excellent basis. The late Rev. W. L. Rham found 

 by analysis that a rich crarden mould contained— 



Clay - 52.4 



Siliceous sand - 36.5 



Calcareous sand 1.8 



Carbonate of lime 2.0 



Humus - - 7.3 



in 100 parts; and that 

 it had a specific gravity of 2.332, that is to say, a gal- 

 lon of it weighed rather more than 2^^ gallons of 

 water. According to the same excellent authority, a 

 medium soil had a specific gravity of 2.401 ; and a 

 poor soil 2.526, being in the proportion to an equal 

 bulk of water, as 2 J to 1, nearly. The latter descrip- 

 tion of soil contained a large proportion of siliceous 

 sand, and wherever this is in excess, it renders the 

 soil so deficient in cohesiveness, that it does not retain 

 moisture. 



With the simple apparatus described in Mr. Rham's 

 Essay, any intelligent man may ascertain the compo- 

 nent parts of a soil, and detect adulterations in the 

 substances which are sold as guano, bone-dust, 6cc. ; 

 the necessity for this has been proved in a remarkable 

 manner recently; a quantity of the former having 

 been found by analysis to contain thirty per cent, of 

 sand, and thirty per cent, of water. 



