162 PEEMANENT NUESEKIES. 



4. Urine. — Urine is a very powerful manure, and human 

 urine is the richest of all, containing, as it does, more than 30 per 

 cent of urea or nearly 8 times as much again as that of the cow 

 and more than 4 times as much again as that of the horse. Urine 

 should never be used except after putrefaction, and then, too, large- 

 ly diluted with water or mixed with earthy ira'^ters, as in an un- 

 mixed state it would be very injurious to plants. During the 

 putrefaction a large amount of ammonia is formed and must be 

 fixed by the addition of gypsum, whereby the volatile carbonate of 

 ammonia is converted into the non-volatile sulphate. 



5. Blood. — Blood is a very powerful manure, not only on 

 account of its nitrogen (nearly 16 per cent.) but also of the nu- 

 merous useful salts it contains, chief among them, after common 

 salt, being phosphates. Blood may be applied to the soil in a 

 liquid or dried state, either alone or mixed with other manures. 



6. Composts. — The meaning of the term compost has already 

 been explained under the head of weak manures. There also it 

 was said that composts are strong, if they contain a large proportion 

 of nitrogenous matter or phosphates. Hence nothing special need 

 be said here. 



SECTION V. 



Permanent nurseries. 



The main points to consider as respects the establishment and 

 maintenance of a permanent nursery are : — 



(1) Choice of site. 



(2) Area of the nursery. 



(3) The form of its boundary. 



(4) Fencing. 



(5) General perparation of the soil. 



(6) Watering. 



(7) Laying out of the beds, paths, &c. 



(8) Preparation and management of the seed-beds. 



(9) Preparation and management of the nursery lines.. 



ARTICLE 1. 

 Choice of site. 



In choosing a site for a permanent nursery we have to consider 

 its two elements : — (i) soil, and (iij locality. 



Soil. — It is an erroneous idea that transplants should neces- 

 sarily be raised in soil similar to that of the forest into which they 

 are to be put out. The nurseryman is iu every case required to 



