MANURES 73 



fruit crops. A smaller quantity, however, is safer for the flower border, 

 applied in spring and lightly forked into the soil as the plants are 

 about to begin growth. The best time as a rule for dressing the soil 

 with superphosphate is in spring when seeds are being sown. If the 

 soil is in a poor condition, superphosphate by itself will not be of much 

 use, and the ground should have had a good dressing of farmyard 

 manure the previous autumn to make it valuable. 



Bones. — The value of Bones as a phosphatic manure has long been 

 recognised, and many gardeners are very partial to having a sprinkling 

 of ' bone-meal ' or ' bone-flour ' always mixed with soil when repotting 

 or replanting. Bones are, however, a very slow-acting manure, but 

 the process of decomposition and consequent quicker action may be 

 assisted by having them finely crushed. In the form of bone-meal, 

 unadulterated and unsteamed bones contain about 45-50 per cent, of 

 phosphate of lime, and also a small quantity — 4-5 per cent. — of 

 ammonia salts. Steamed or boiled bones contain about 60 per cent, 

 of phosphate of lime, but not so much ammonia. The phosphate of 

 lime, however, is not soluble in pure water, but when acted upon by 

 the carbonic acid in ordinary water, rain &c. it gradually dissolves and 

 fertilises the soil. 



A manure called dissolved bones or hone superphosphate is produced 

 by mixing a certain quantity of sulphuric acid (or oil of vitriol) vdth 

 raw bone-meal — about 9 cwts. of sulphuric acid to 20 cwts. of bone- 

 meal. About one-third of the insoluble phosphate of lime in the bones 

 is changed by the chemical process into a soluble condition, and is thus 

 more readily available for the roots of plants. A reasonable dressing 

 for fruit and vegetable crops is about 1-2 lbs. to every ten square yards, 

 and may be given in winter or spring. 



Basic Slag. — This is a dark coloured powdery substance also 

 known as ' Thomas's phosphate ' and ' basic cinder.' It contains a 

 good deal of oxidised iron (commonly called ' rust '), but not to any 

 injurious extent. Its chief value lies in the amount of lime it contains 

 in the form of a phosphate, and it is particularly valuable for improv- 

 ing soils which are destitute of lime or chalk, and also vegetable or 

 animal remains called humus. It is best applied in autumn or winter 

 at the rate of 4-8 ounces to the square yard, or 10-20 cwts. to the 

 acre, more or less according to the poverty of the soil in regard to lime 

 and humus. It is good for fruit trees and most garden crops, but will 

 give disappointing results if applied in spring instead of aiitumn or 

 winter as recommended. 



Potash.^ — While nitrogenous food increases luxurious growth, and 

 phosphatic food large crops of fruit, potash increases the quality and 



