56 WATERING, [chap. m. 



for this reason, the water in hothouses and 

 greenhouses is generally kept in an open vessel 

 in the house some hours before it is given to 

 the plants. In some cases, the water may be 

 much hotter than the temperature in which the 

 plants are grown ; and the effect of hot water, 

 not heated to above 200°, in forwarding bulbs 

 is astonishing ; but it must be observed that it 

 should never be poured on the bulbs, or on the 

 leaves, but on the earth near the rim of the pot. 

 Hot water is also very efficacious in softening 

 seeds with hard coverings when soaked in it; 

 and some of the seeds of the New Holland 

 acacias will not vegetate in this country till 

 they have been actually boiled for about a 

 minute ; the germinating power of other thinner- 

 skinned seeds is, however, destroyed in a few 

 seconds by immersion in boiling water. 



Water is also very useful when poured on 

 manure, as many manures are much best in a 

 liquid state. For example, if a gallon of water 

 be poured on an ounce of guano manure, and 

 allowed to stand twenty-four hours, the liquid 

 may be safely given to plants in pots, which 

 would have been killed by the guano in a dry 

 state. 



Tlie following is a summary of the rules to 

 be observed in watering. — Never to suffer 

 plants to become so dry as to wither their 

 roots, and yet never to saturate the soil so 

 completely as to exclude the air; but to re- 

 member that water is never so advantageously 

 given to plants as when it is kept in detached 

 globules by the admixture of air, which it is when 



