4 The Spraying of Plants. 



as soon as the cultivation of plants began to attract serious 

 attention. The immediate causes which led to the practice 

 were undoubtedly the same as those now existing. Foliage 

 almost invariably looks brighter and fresher when wet, and one 

 instinctively feels that if the appearance of a plant is improved 

 by a certain operation, the general health of the plant is 

 improved to an equal degree. The removal of insects or any 

 injurious substances would have a similar effect, and all good 

 gardeners would feel a temptation to improve their plants in this 

 simple w^ay. 



Insects and diseases have unquestionably troubled cultivators 

 from the time plants were first grown. Remedies would natu- 

 rally be sought, and it appears that these older gardeners were 

 controlled by the same feeling which even to-day often mani- 

 fests itself in connection with the taking of medicine : the 

 worse the drug smells or tastes, the more good it is supposed to 

 do. Early in the seventeenth century Parkinson advised the use 

 of vinegar to prevent canker on trees, and the recommendation 

 was supposed to rest upon a very firm foundation. 1 One old 

 record 2 giving instructions for making liquid applications of an 

 insecticide reads as follows : " Cantharides (Cantarides) are 

 flies which attach themselves to the branches near the upper parts 

 of trees, especially on the ash. They may be destroyed by 

 pouring or throwing on the tops of the trees, by means of a 

 small pump, water in which has been boiled some rue." Ruta 

 graveolens is probably meant. This herb has a strong, heavy, 

 and very disagreeable odor, and a sharp, bitter taste. If such 

 qualities make a plant a good insecticide, rue should be one of 

 our most valuable remedies. It seems very probable that the 

 idea of selecting materials which are offensive to the senses was 

 uppermost in the minds of those who first had occasion to use 

 them, for most of the earlier substances recommended are of 



1 John Parkinson, "Paradisus," The Ordering of the Orchard, Chap. viii. 550. 

 1629: "The canker is a shrewd disease when it happeneth to a tree; for it will 

 eate the barke round, and so kill the very heart in a little space. It must be 

 looked into in time before it hath runne too farre ; most men doe wholly cut away 

 as much as is fretted with the canker, and then dresse it, or wet it with vinegar or 

 cowes pisse, or cowes dung and urine, &c. untill it be destroyed, and after healed 

 againe with your salve before appointed." 



2 "La Theorie du Jardinage," 166, 1711. See also Deane, "The Newengland 

 Farmer," 177-184. 



