658 



Mode of destroying Insects mid Vermin. 



inch from the internal one. This is filled with water ; and 

 when the Hd (r) is put on. its edge goes down into the water, 

 and forms an air-tight joint or valve. The gas passes off by 

 the tube (r/), likewise made of tin, which should have two 

 bends at right angles ( fig. 127.), in separate pieces, to permit 

 its motion in all directions. 



Into this vessel the previously determined quantity of am- 

 moniacal liquor is to be put; and about half a pound of 

 quicklime, in small pieces, for every quart of liquor, is to be 

 added. The cover is then put on, and the tube inserted into 

 some convenient opening in the lower part of the house, 

 taking care that no plants are very close to the aperture. 



In this way, which I find a great improvement upon the 

 plan of evaporating the fluid, the gas is abundandy disen- 

 gaged ; the slacking of the lime produces sufficient heat, with- 

 out the application of fuel ; and the ammonia is in a causdc 

 state. 



Those who cannot procure this apparatus will probably 

 not be able to get the liquor either ; but should they get 



the liquor, a small still, 

 or even a watering-pot, 

 placed within the house 

 in this position (y^f. 128.), 

 may be substituted. 



Ammoniacal liquor 

 may be used with safety 

 for washing dirty pines, 

 and the wood and buds 

 of vines ; to kill the red 

 spider early in their sea- 

 son of appearing. Plants 

 in pots, when very dirty, 

 may even be dipped into 

 it, diluted with 'an equal quantity of water; and soon after 

 dipped into, or syringed with, pure water, to wash it and the 

 dead insects off. A single very filthy plant, with close hard 

 leaves, such as a Panddnus, a Bonaparter/, &,c., may be covered 

 with an inverted barrel, and die gas applied to it alone, the 

 plant being previously and subsequendy syringed. 



In every kind of house, it is well to syringe gently before 

 applying the gas, as the water absorbs some of the gas, and it 

 thus acts more powerfully; but, in every case, the house 

 shoukl be syringed afterwards. 



In very humid houses, radier more of the gas than one fifth 

 of the volume should be applied ; the quantity, however, will 

 in general be best found by the observation of the intelligent 



