Early History of Liquid Applications. 11 



strength necessary to overcome the organism against which 

 they were applied. He writes as follows : 



"Insects may be annoyed, and oftentimes their complete 

 destruction effected, by sprinkling over them, by means of 

 a syringe, watering-pot, or garden engine, simple water, soap- 

 suds, tobacco water, decoctions of elder, especially the dwarf 

 kind, of walnut leaves, bitter and acrid herbs, pepper, lye of 

 wood ashes, or solutions of pot and pearl ashes, water impreg- 

 nated with salt, tar, turpentine, etc. ; or they may be dusted 

 with sulphur, quicklime, and other acrid substances." An- 

 other article, one mentioned by Lindley, 1 is vinegar, and he 

 says that it is of considerable value for destroying insects. 



With such a battery of powerful materials directed against 

 them, it is a wonder that so many insects we now have to con- 

 tend with should still exist. The very number of the materials 

 named is an indication of weakness ; for if any of them had 

 really possessed very decided merit, there would have been no 

 necessity for the existence of the rest. Some of them are really 

 valuable, and are in use at the present time, yet it is true that 

 we are still on the lookout for something which is superior to 

 the remedies now at hand. 



The value of hot water as an insecticide has long been 

 known. Fessenden quotes 2 London as saying: "Saline sub- 

 stances mixed with water are injurious to most insects with 

 tender skins, as worms and slugs ; and hot water, when it can 

 be applied without injuring vegetation, is equally, if not more 

 powerfully, injurious. Water heated to 120 or 130 degrees 

 will not injure plants whose leaves are expanded and in some 

 degree hardened ; and water at 200 degrees or upwards may be 

 poured over leafless plants." In a later work, 3 London says : 

 "Mr. Swainson advises for the destruction of the aphis 'the 

 application of warm water, sufficiently hot to destroy aphis 

 without injuring the trees : more will be thus destroyed than 

 either by repeated application of the syringe or by the use of 

 tobacco water. . . . Two or three applications of warm water 

 will destroy nearly all the insects.'" The remedy was also 

 frequently mentioned in horticultural journals. 



1 Lindley, " Guide to the Orchard and Kitchen Garden," 1831, 509. 



2 Fessenden, "New American Gardener," sixth edition, 1832, 169. 

 8 " London's Encyclopedia of Gardening," 1878, 795. 



