NOTES. [^19] 



heights. The ratchet for vertical adjustment subserved this purpose satisfactorily. 

 Where it is desired to spray the base and interior of the plants from beneath, the 

 nozzle arms must necessarily be carried near or on the ground, and with medium to 

 small cotton this method also sprays the top sufiSciently well, but if the growth be 

 heavy and dense it proves better to set the forks higher for more thoroughly poison- 

 ing the tops. 



The stirrer pump worked admirably ; but a larger pump of the same kind was 

 necessary to treat a greater number of rows, to ascertain how large a number it is 

 possible or advisable to spray at a time. \Vbil© the large pump was being con- 

 structed and shipped the time limited by my orders expired. 



Four rows may be set as the number it is most practical to treat at a time with 

 the kind of machine in question. 



The springs of the fork-arms should be larger and have a longer bend than in 

 the samples taken, since the unyieldiug attachment of the stem-pipes to the stiff sup- 

 porting x)ipe above throws on the springs much greater strain than occurs in the 

 machines having descending parts hung to operate independently of each other. 



Until my time had expired worms were not abundant enough to study the effects 

 on them of the coarser and finer sprays applied, but the coarser spray was more in- 

 jurious to tho foliage with poisons, and still more so with petroleum. 



The standard form of eddy-chamber nozzle was used with discharges of different 

 sizes. The smallest discharge holes, of -5^ to ^^ of an inch diameter, with very high 

 pressure, gave the most satisfactory results. 



The "actual cost, and the actual area covered by a given amount of liquid," vary 

 greatly with the width between the rows, the sizes of the sprays and of the plants, 

 with the number of nozzles, with the amount of pressure applied and the volume 

 capacity of the pump, the velocity at which the machine is drawn, &c. On account 

 of the. complexity of the question, and especially because of leakage from imperfect 

 pipe-joints and for want of other and larger apparatus, the question could not be 

 solved with any exactness. 



Note 57 (p. 326). — The text of this editorial has been given on p. 37, where it is 

 also shown that Mr. Stelle's claim is unwarranted. We have thought it of sufficient 

 historical interest to show upon what the claim was based, and the following passages, 

 copied verbatim from a report made by him while employed by the commission, in 

 accordance with instructions to prepare an account of the past history of the insect, 

 is of interest in this connection. The full report is not published, because it is little 

 more than a compilation from the Department report for 1879 — often word for word : 



" In June of 1872, the National Agricultural Congress was organized at Saint Louis, 

 Mo., and Prof. C. V. Riley, who was present and took part in the organization, de- 

 livered before the body a lecture on economic entomology. Allusion to the cotton 

 worm was made in the course of the lecture, which lead General William H. Jackson, 

 of Nashville, Tenn., and Dr. J. O. Wharton, of Ferry, Miss., to ask for the suggestion 

 of a remedy. In response, Professor Riley gave it as his opinion that Paris green, so 

 effectual as- a remedy' against the Colorado potato beetle, would, in all probability, 

 prove equally effectual as a remedy against the cotton worm. This, so far as I have 

 been able to learn, (and I have worked the matter up with great care), was the first 

 hint ever thrown to the public in that direction ; and there is no risk in asserting that 

 the day in which the hint was thrown out marked the beginning of one of the most 

 important periods in 1>he history of the cotton worm up to the present time: the 

 period of successfully combating it with poiaons ; in a word, the period of first effect- 

 ually combating it in any way to an entire saving of the crop. 



"Later in the same season, (1st August), the writer of this paper, who had not then 

 heard of Professor Riley's suggestion, recommended, as agricultural editor of the 

 Mobile Register, the use of Paris green as a cotton worm destroyer, and Capt. Isaac 

 Donavan, of Mobile County, Alabama, immediately applied it, in obedience to the 

 recommendation, wkh great success. This is the earliest application of Paris green 

 to the cotton plant that I have been able to trace to date.'' 



"In May of the next year (1873), the National Agricultural Congress assembled at 

 Indianapolis, Ind., where Professor Riley again addressed the meeting, referring at 

 length to Paris green as an insecticide, and unhesitatingly recommending it as a 

 remedy against the cotton worm. His address was widely published through the 

 papers, especially in the South, and thereupon hundreds of planters went at once to 

 applying the poison, meeting with good success in every case where the directions 

 given by Professor Riley were faithfully followed." 



With regard to the second paragraph which we have just quoted truth requires 

 us to state that the August (1872) article in the MoMle Register (see p. 37) did not 

 appear in the -agricultural department of that paper but in the regular editorial 



