298 



THE TROPICAL AGRICULTURIST. [October i, 1885. 



the privilege of beiug introduced to Mr. Jnhn G. 

 Horsey, the maiiagiug director of the company, who, 

 finding that I was iuterestcl in the subject, kindly 

 invited me to visit the worlds, and I was well repaid 

 for the hour and a half spent in following the life- 

 history of a brush, more especially as every detail 

 was carefully pointed out and explained by the very 

 intelligent an 1 obliging manager of the works, which 

 are situated in Copperfield Road. Mile End. Euormons 

 quantities of ba?8 or Piassaba, as well as Kittool are 

 u.'ie 1 by this.company, and as they have lai ge contracts 

 both for the (rovernmeut as well as for some of the 

 principal railway oorapanies, are always very busy. 

 At the time of my visit the employes were for the 

 most pirt at work ou Piassava. — Gardeners' Chronicle. 



IN.SECTS AISD AGRICULTURE. 



Pktroleitm, in its various forms, has long been 

 recoi^nised as onfc of the most effective insecticides 

 in ovir possession, all only substances being particularly 

 deadly to insects. Unfortunately they are also injur- 

 ious to plants, and one of the problems, the solution 

 of which I* have had in mind for many years, has 

 been their use in such dilution as to kill the insect 

 without injury to the plant. Refined kerosene has been 

 used to a limited degree by forcible attenuation in 

 water and spray, while some plants withstand doses 

 of the pure oil. But the safe and general use of 

 kerosene for the purpose under consideration dates 

 from the year 1880. Of the various substances used 

 in al tempts to emulsify and mix kerosene with 

 water none are more satisfactory then soap and 

 milk, both being everywhere accessible and cheap. 

 Milk was fir.^t suggested in 1880 by Dr. W. S. Barnard, 

 while carrying on experiments for me against the 

 Cotton-worm, and subsequent experiment, especially 

 by another of my assistants, Mr. H. G. Hubbard, 

 has given ns the simplest and most satisfactory 

 method of m.iking the emulsion quickly and perman- 

 ently. All eniul.'-ion resembling butter can be produced 

 in a few minutes by churning with a force pump 

 two parts of kerosene and one part of sour milk in a 

 pail. The liquids should be at about blood-heat. 

 This emnlsion may be diluted with twelve or more 

 parts of water to one part of emulsion, thoroughtly 

 mixed, and may be applied with the force-pump, a 

 p-.iy nozzle, or with a strong garden syringe. The 

 strength of the dilution must vary according to the 

 nature of the insect to be dealt with, as well as to 

 the nature "f the plant; but finely sprayed in twelve 

 spirts of the water to one of the emulsion it will 

 kill most insects without injury to the plant. An 

 equallv good emulsion mrjr be made as follows; — 



Kerosene, 2 gal.; common soap, i lb.; water, 1 

 gal. Heat the mixture of soap and water, and add 

 it 1)0 ling hot to the kerosene. Chuin the mixture 

 by means of a force pump and spray mozzle for 

 five or ten minutes. The emulsion, if perfect, forms 

 a cream, which thickens on cooling, an.l adheres 

 without oiliness to the surface of glass. Dilute with 

 cold water before using, to the extent to which experience 

 will indicate is best. 



The simplest discoveries are often the most valu- 

 able, and this discovery of so simple and available a 

 means of dihiting, ad libitum, oil with water is 

 important and far-reaching in its practical application. 

 Pyeethkuji. 

 Pvrethrum roseum, a plant native to the Asiatic 

 countries south of the Caucasus Mountnin.s. and 

 Pyretbrum cinerariicfolium, a native of Dalmatia, 

 have long been known to possess insecticide properties, 

 uspecinlly in the powder from the dried and pulver- 

 ised tlowcrs. The powder, .sold under various names 

 by druggists, was chiefly used against household jiests, 

 however ; and though Mr. 0. AVillMmet, as early as 

 KSoT in France, and Jlr. William S:umders, in 1879, 

 in Can.adn, tried it in powder form on some that 

 are injurious to plants, its importance as a fielil in- 

 Boctido did not appear till in 1880, when, in prosecuting 



the work of the United States Eitomological Oom- 

 mission, we discovered that it could be used in liqudl 

 solution. Both species proved to be hardy throughout 

 the greater portion of our country, and Mr. G. N. 

 Mdco, of Stockton, Cal., has for some years cultivated 

 cinerariffifolium quite extensively at great jirofit, the 

 product being sold under the name of " Buliacli." 

 The insecticide property dwells in a volatile oil. It 

 acts only by contact and its action on many larv;o 

 is marvellous," the smallest quantity in time paralysing 

 and ultimately killing. Its influence in the open air 

 is evanescent, in which respect it is far inferior to 

 the arsenical products; but being perfectly harmless 

 to plants, it can frequently be used on vegetables 

 where the more poisonous substances would be dangerous. 

 Pyretbrum is supposed to have no effect on the 

 higher animals, but that is a mistake, as my own 

 recent experience is that the fumes in a closed room 

 have a toxic influence, intensifying sleep and inducing 

 stupor; while the experience of Professor A. Graham 

 Bell with the powder copiously rubbed on a dog 

 showed that the animal was made sick aiui was 

 affected in the locomotive organs very much as insects 

 are. The wonderful influence of this powder on 

 insects has led me to believe that it might prove 

 useful as a disinfectant against fevers and v.vrious 

 contagious diseases by destroying the microzoa and 

 other micro-organisms, or germs, which are believed 

 to produce such diseases. It should be tried for 

 that purpose. It is remarkable that these two plants 

 of all the many known species of the genus should 

 alone possess the insecticide property. 

 Bisulphide of Cadbon. 

 Of all insecticides to be used against root-feeding 

 or hypogean insects, naphthaline, sulpho-carbonate of 

 potassium, ansd bisulphide of carbon are the chief. 

 Dr. Ernst Fischer, in a recent w(jrk, has shown that 

 naphthaline in crystal may be satisfac torily used un- 

 derground, destroying by slow evaporation. But 

 bisulphide of carbon still holds the first place in 

 France against Phylloxera vastatrix. It is conveyed 

 beneath the ground at the rate of one-half to one 

 kilogram per Vine by special injectors, or by more 

 complicated machinery, drawn by horses. I believe 

 that petroleum emulsions will supersede it as an un- 

 derground insecticide, and prove to be the best we 

 have, cheapness, safety, .and ofliciency considered. 

 After the discovery of a .satisfactory insecticide, how- 

 ever, various important problems must be solved, and 

 particularly how to apply it to greatest advantage, 

 having safety to man and stock, harmlessness to pl»nt, 

 and economy in mind. The .solution of these points, 

 and others that the peculiar habits of the insect to 

 be controlled involve, brings us to the question of 

 mechanical contrivances and appliances; for while 

 much ingenuity has been exhibited in devising mechan- 

 ical means of dureetly destroying noxious insects 

 without insecticides, it is chiefly in the proper application 

 of these last that the greatest mechanical advances 

 have been made both in this country and in Europe. 

 Here, again, the subject is so vast that I cannot 

 enter into details. 



It will already have been gathered, from what has 

 precedeil, that the chief insecticides are applicable in 

 liquid form, and as Hquids have an advantage over 

 powders in field use, instruments for atomising and 

 distributing liquids coustitute the most important part 

 ot insecticide machinery. The d'sidenita in a spray- 

 nozzle arc, ready regulation of tho volume to be 

 throwu; greatest atomising power, with least tendency 

 to clog ; facility of cleansing or ready separation ot 

 its component parts; cheapness, simplicity, and ad- 

 justability to any angle. 



I will content myself with exhibiting one which 

 meets, perhaps, more of these re(iuiremouts that any 

 other in use, and which works_ on a new principle 

 appli('able to many other purposes than th;it for 

 which it was designed. It is what has been described 

 and illustrated in my late ofKcial repo ts as the eddy 

 or cyclone nozzle, and consists of a small circular 

 chamber with two flat sides, one of them screwed 



