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by one well skilled in the delicate labours of minute 

 analysis ; but there are processes within the reach of an 

 accurate observer, by which the grosser constituents can 

 be ascertained, and which would richly repay the trouble. 

 1st. To ascertain the quantity of organic matter in a 

 soil : 



Dry a sample of the earth in an oven or pot, placing 

 it on paper, and taking care that the paper is not burned; 

 then weigh and burn it effectually, until the dark colour, 

 which the decomposed matter communicates to the soil, 

 has disappeared ; after this weigh it again, and the dif- 

 ference of weight will indicate the quantity of humus 

 which the soil contained. 



2nd. To ascertain the quantity of saline matter : 

 Take a given quantity, say 1 Ib. weight, of dried earth, 

 and pour upon it three half pints of boiling rain-water ; 

 stir and agitate the whole, and allow it to settle; then 

 pour off the water in which the salts will be dissolved, 

 and boil it until the whole be evaporated, when a few 

 grains of solid matter will remain, consisting of mixed 

 saline substances, which, being soluble in water, are com- 

 municated in a liquid state as food to plants. 



3rd. To ascertain the quantity of silica and alumina: 

 Pour on a sample of dried earth a quantity of rain-water, 

 and agitate it well ; then pour off the muddy liquid into 

 a separate vessel, and repeat the operation until the water 

 is no longer muddied by its contact with the earth : thes 

 muddy waters should all be put together and allowed to 

 settle ; the deposit which they leave will show the amount 

 of clay in the soil ; the earth which was washed contains 

 only sand ; both these proportions should again be dried, 

 and weighed separately. 



4th. To ascertain the quantity of lime : 

 Take a portion of dried earth from which the organic 

 matter has been burned away ; then add to it a mixture of 

 muriatic acid and water, stirring it well until it ceases to 

 effervesce, and after a few hours strain off the liquid, and 

 dry and weigh the soil again ; the loss will indicate the 

 proportion of calcareous matter it contained. 



