y1iff('] THE FORCING GARDEN. 757 



heated by Knings of dung, without fire-heat, will liavc all 

 their insects killed, or be kTept free from them, if they were 

 clean when planted by the effluvia of the dung." Mr. Knight 

 concludes, " that the destructive agent in this case is am- 

 moniacal gas, which Sir H. Davy has found to be instantly 

 fatal to every species of insect; and if so, this might be ob- 

 tained at a small expence, by pouring a solution of crude 

 muriate of ammonia upon quick lime. The stable or cow-house 

 would afford an equally elhcient, though less delicate fluid. 

 The ammoniacal gas, Mr. Knight supposes, might be impelled 

 by means of a pair of bellows among the leaves of the infected 

 plants, in sufficient quantity to destroy animal life without 

 injuring that of the vegetable; and, he adds, it is a very inte- 

 resting question to the gardener, whether his hardy enemy, 

 the red spider, will bear it with impunity." 



Griffin recommends : To one gallon of soft rain-water add 

 eight ounces of soft green soap, one ounce of tobacco, and 

 three table-spoonfuls of turpentine ; stir and mix them well 

 together in a watering-pot, and let them stand for a day or 

 two. When you are going to use this mixture, stir and mix 

 it well again; then strain it through a thin cloth. If the fruit 

 only be infested, dash the mixture over the crown and fruit 

 with a squirt, until it be all fairly wet, and that which runs 

 down the stem of the fruit will kill all the insects that are 

 amongst the bottom of the leaves. When young plants are 

 infested, take them out of their pots, and shaking all the earth 

 from their roots, (tying the leaves of the larger plants toge- 

 ther,) plunge them into the above mixture, keeping every [)art 

 covered for the space of five minutes ; then take them out and 

 set them on a clean place, with their tops declining downwards, 

 for the mixture to drain out of their centre. When the j)lants 

 are dry, place them in smaller pots than before, and j)lungc 

 them into the bark-bed." 



Muirhcad, in a communication in the Mem. of the Cale- 

 donian Horticultural Society, recommends immersing the plants 

 in a tub of water, in which there has been mixed one pound 

 of sulphur to every watering-pot full of water. W ith a bit of 

 bass-mat fixed to a small stick, which he dips in water, lie dis- 

 places as many of the insects as he can ; he then immerses the 



