editor's table. 



^biter's Cable. 



Ammonia in IIothouses;. — When it was discovered that ammonia is derived from the atmo- 

 sphere, and that it descends in rain, a new light was thrown npon the refreshing and invigo- 

 rating effect of heavy showers, which act not merely by their water, as once was thought, 

 but also by the carbonate of ammonia which they bring down. So far as agriculture is 

 concerned, this is, however, a truth devoid of possible application, because the volatile 

 carbonate cannot be advantageously used artificially through the agency of the atmosphere. 

 But it is otherwise with gardeners, who have to create an artificial atmosphere in a confined 

 space. It is not a little remarkable, then, that so simple an agent, so easily procured, and 

 applicable with so little trouble, should scarcely ever have been employed in hothouses 

 in the proper manner. Where it has been used, it has been almost invariably when dis- 

 solved in water and applied with a syringe. Professor Lindley at length gives the proper 

 mode of application ; doubtless many have thought of it, but the present will, we believe, be 

 the first correct instructions on the subject in this country. 



The carbonate of ammonia of the atmosphere is suspended, dissolved in invisible vapor. 

 In this state it is incessantly in contact with every part of the foliage. When rain falls, the 

 ammonia disappears for the moment, passing down in the rain drops to the ground, and 

 thence arriving at the roots of plants. But if it is in gardens first dissolved in water, and 

 then thrown ui)on plants with a syringe, natural conditions are by no means imitated. It 

 reaches no part except that on which the water falls, half the upper surface and nearly all 

 the under surface of the foliage is missed, and it is scarcely detained even upon the parts 

 which the water actually touches. The proper course is to throw it into the air in the form 

 of gas ; this is easily effected in the following manner : — 



When a greenhouse or hothouse is shut up, warm and damp, rub upon the heated pipes, 

 the flues, or a hot piece of metal, a small piece o'f carbonate of ammonia with some water (not 

 dry) ; the peculiar smell of smelling salts will be instantly perceived, and, if this is done at 

 the two ends of a house, as well as in the middle, the air will rapidly receive a sufiicient 

 charge of the substance. After it has been allowed to remain about the plants for a short 

 time, some gardeners would syringe their houses freely ; but it is doubtful whether that is 

 the best plan, provided the air of the house is naturally damp. The effect of this simple 

 application is very remarkable, quickly producing a visible change for the better in the 

 appearance of the plants. 



But caution must be used in the application. A piece of carbonate of ammonia as large as 

 a quarter of a dollar is sufficient for a charge in a stove 40 feet long ; and it is indispensable 

 that it should be volatilized by ruhhing it in water, otherwise its causticity is too great, and 

 leaves are burnt. 



Answers to Correspondents. — (A. C. Ivy.) By a little management you may have yovir 

 ivy to cling perfectly. Whenever a branch grows without attaching itself to the wall, cut 

 off the loose part close to a leaf, beneath which the attachment is perfect. Continue this 

 X)rocess till the wall is covered, and ever afterwards cut away all hanging branches, or by 

 the force of the wind thoy will detach others besides themselves. When the ends of growing 



