AUXILIARY AK"D EXCEPTION^AL MAJEURES. 93 



Cotton-cakc-dust, and Malt-dust, — The value of these 

 substances is chiefly dependent on the large quantity of 

 nitrogen which they contain. 



Cotton-cake-dust has recently been tried with extra- 

 ordinary effect on poor cotton lands. This could not be 

 due altogether to the connection which existed between 

 the chemical properties of the manure and those of the 

 crop. Their value as feeding-stuffs hinders their use as 

 manures. 



Fish refuse contains nearly two per cent, of nitrogen, 

 and one per cent, of phos^^horic acid. It answers well as 

 a manure for both wheat and root crops when made into a 

 compost with its own weight of soil, and allowed to de- 

 compose before being applied. Fish guano is a manu- 

 facture of the refuse from oil-pressing and fish-curing es- 

 tablishments by pressure and treatment with sulphuric 

 acid. 



Bullock's Blood is used on a large scale as a manure, 

 but chiefly for mixing with other fertilizers. In its 

 natural state blood contains about three j^er cent, of 

 nitrogen; when dried it contains twelve per cent. It 

 makes an excellent manure for turnips when mixed with 

 bone-dust or phospiiatic guano; and, mixed with peat or 

 mould, may be very advantageously applied as a top- 

 dressing to wheat crops and to grass land. 



Sea-weed is largely used as a manure on some parts 

 of the coast. It is especially suited for the potato crop, 

 which requires much potash — a large mineral constituent 

 of sea-weed. Sometimes it is used as a top-dressing to 

 grass land. The action of sea-weed is the same as a green 

 crop plowed in. It contains all the ordinary constituents 

 of land plants. As it putrities rapidly, it forms a quick 

 manure. It is applied at the rate of twenty to thirty 



