MANUKES, THEIE KINDS AND USES. 53 



The carbonate has too high a value as a drug to allow it 

 to be used by the gardener, except perhaps on a very 

 small scale, and experimentally in the green-house. 

 For such crops as are grown for their leaves, as cabbage 

 and spinach, these salts are admirably adapted; but in 

 the case of potatoes, large doses, as the physician would 

 say, are contra-indicated. 



LIQUID MANURE. 



In China and Holland, liquid manuring for the most 

 valuable crops is extensively practised. As the urine of 

 all animals is much rfcher than the solid excrements 

 (that of the horse containing thirty-one pounds of ni- 

 trogen to the ton, whereas the solid excreta only contain 

 nine pounds), it has a relatively higher agricultural 

 value, and should be saved with care proportioned to its 

 efficacy. The nitrogen being in a more available form, 

 if applied to crops in the liquid state, it will be more 

 valuable in consequence of its solubility. When plants 

 have reached the stage of rapid and steady growth, ap- 

 proaching maturity, their vital energy and the absorptive 

 power of their roots will enable them to profit wonder- 

 fully from an application of liquid manure, for which 

 reason the cauliflower and the cabbage are treated to 

 food in this form just before the former is expected to 

 " curd," and the latter to head. 



When seedling plants have to be watered at the time 

 of transplanting, a weak liquid manure would help them 

 to start better than pure water. 



Urine is too "strong" to be allowed to come in direct 

 contact with seed or with roots, and should first be al- 

 lowed to ferment, and then be diluted with five or six 

 parts of water. In its fresh state it contains no am- 

 monia, this being formed from urea after putrefaction 

 has commenced. 



Solid manure may be steeped in water until the latter 



