PERN FOES, BRITISH AND EXOTIC. 



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with pure tobacco than to depend on tobacco-paper or tobacco -cloth, either of 

 which develops fumes more or less injurious to Ferns. Even pure tobacco- 

 smoke becomes hurtful when applied too strongly, and a slight dose repeated 

 two or three times will prove more effectual and safer than one strong 

 fumigation. A great deal of inconvenience to the Ferns is avoided by the use 

 of tobacco-steam instead of tobacco-smoke : indeed, we have seen it applied 

 in numerous cases, and have never had to record a serious mishap in connection 

 with its use. Very little observation is needed to demonstrate that it must 

 naturally be a safer process, as, instead of being rarefied by the action of the 

 fire, like tobacco-smoke, it is of a moist nature ; and it must also be more 

 efficacious, inasmuch as, instead of being light, and naturally ascending like 

 smoke, it is heavier than the atmosphere of the house, and, after rising a 

 certain height, it falls on and among the plants like a dew, so that the insects 

 cannot possibly escape the deadly effects of the nicotine deposited everywhere 

 in that way. The excessive bitterness with which everything in the house 

 becomes impregnated by its use also acts as a very efficacious and safe 

 preventive. 



There are many ways of generating tobacco -steam, and a very ingenious 

 machine, called the " Thanatophore," has been invented for the purpose of 

 steaming tobacco-juice and disseminating it in the houses. Syringing hot- 

 water pipes with diluted tobacco-juice will, to a certain extent, help to keep 

 the place free from insects ; but this, although apparently a very simple and 

 primitive method, is almost as expensive as the " Thanatophore," on account 

 of the unavoidable loss of material, and is less effective than the following 

 process, which is simple, safe, and does not require any special tuition or 

 preparation : Put into a deep iron pot, say, 2qts. of tobacco -juice, specially 

 manufactured for steaming and of guaranteed strength, procurable from the 

 principal nurserymen ; then put into the furnace a fire-brick, and when this 

 has become white-hot, take it out of the fire, and straightway put it into 

 the iron pot containing the tobacco-juice, closing the door of the house. We 

 purposely say deep iron pot, as the juice, when hot, has the property of rising 

 considerably, in the same way as milk, and unless this expansion be provided 

 for, only a small part of the material would be used : the greater portion of it, 

 running over the sides of the pot, would be entirely wasted. By the time 

 the brick has completely cooled down, all the nicotine will have been extracted 



