142 FERTILIZING SUBSTANCES. 



riching. These, except those from which oil has been expressed, are 

 however too valuable. Rape seed is thus used in the spring with the 

 greatest advantage. 



Charcoal powder has the property of absorbing noxious vapors 

 from the air and soil, and impurities from water ; it also imbibes oxy- 

 gen from the air. This is therefore very valuable to mix with any 

 other kinds of manure ; it is also used advantageously alone. Gar- 

 den seeds sprout in it with great quickness and certainty. Soot 

 from coal or wood is also very valuable, used in the same manner. 

 Its immediate effects are attributed to its ammonia, etc. Peat likewise 

 supplies a great quantity of inorganic matter. Peat bogs drained, and 

 lime and clay afterwards applied, becomes excellent corn-bearing soil. 

 Peat mixed with ammoniacal liquor, or when half charred and blended 

 with the liquid of the farm-yard, is thought to form the best of com- 

 post for plants. 



A ton of the several kinds of straw or hay in manures, will 

 return to the soil the following quantities in pounds, respectively, 

 of inorganic matter : Wheat-straw, from 100 to 360 ; oat-straw, 

 100 to~!80; hay, 100 to 200: barley-straw, 100 to 120; pea- 

 straw, 100 ; bean-straw, 60 to 80 ; rye-straw, from 50 to 70 ; dry 

 potato tops, 100 ; dry turnip tops, 260 ; and rape-cake, 120. The 

 effect of these on particular plants is not however always in exact 

 proportion to the absolute quantity. If the fertilizing value of these 

 is to be estimated by the quantity of nitrogen they contain, as some 

 suppose, the following would be the proportion, in pounds, of some of 

 the best : Fir or pine saw-dust, 250 ; oak ditto, 180 ; barley straw, 

 180; wheat ditto, 80 to 170; oat straw, 150; farm-yard, 100; buck- 

 wheat, 85 ; green grass, 80 ; fresh sea-weed, 80 ; potato tops, 75. 



It is said that 80 Ibs. of meadow-grass ploughed in is equal to 100 

 of farm manure. The application of carbon to plants must be im- 

 portant, since it is believed that each element in decaying plants is 

 capable of affording food to the living plant. 



Animal substances used for fertilizing the soil are mostly the flesh, 

 blood, bones and hair of animals, and the bodies of fish, with the solid 

 and liquid matters of animals and birds. These act more powerfully 

 than vegetable substances, seeds excepted. Flesh is not much used. 

 Fish, in this country, are applied quite extensively in some parts, and 

 are very efficacious, though on ordinary soils, they are quite too strong 

 when applied directly to it. They should be made into compost 

 with large proportions of earth. 5 barrels of fish to 20 loads of com- 

 post is ample for an acre. The refuse of skins boiled for glue, fish 

 oils, and of the dried fat of animals, hair, woollen rags, etc., when 

 made into compost, is much more effectual than vegetable substances. 

 Insects are used in large quantities in parts of Europe. Blood makes 

 an excellent compost, but it is little used. As used by the Sugar 



