October 6, 1893.] 



SCIENCE. 



195 



LETTEES TO THE EDITOR. 



^*.^Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as a proof of good faith. 



On request in advance, one hundred copies of the number con- 

 taining his communication will be furnished free to any corres- 

 pondent. 



The editor will be glad to publish any queries consonant with 

 the character of the iournal. 



A Recapture From a River Pirate. 



The Jackson River of Bath aud Alleghany counties, 

 Virginia, affords an interesting example of recapture of a 



raphy is represented by the dotted lines, the existing 

 topography by the line C D. It is evident that in per- 

 mian time Back Creek and Meadow Fork made a con- 

 tinuous stream, occupying a synclinal valley. The first 

 capture was that of the headwaters of Jackson River by 



tributary A of Back Creek, as the folds of permian time 

 were higher to the east and died away westwardly. At a 

 later date, probably at the time of the cretaceous tilting, 

 when the hills sloping east became steeper, tributary B, 

 of Jackson River, beheaded the pirate and recaptured her 

 own waters. Collieb Cobb. 



Chapel Hill, N. C. 



portion of a stream from "a river pirate." Last winter I 

 directed the attention of Messrs. Charles Baskerville and 

 R. H. Mitchell, students of the University of North Caro- 

 lina, to the interesting problem of adjustment presented 

 by this stream. A result of their investigation is given 

 in the accompanying sketch maps. 



Pig. 2 presents a map of the stream in its present rela- 

 tions, and a geological section of the country. In fig. 1 

 we have the streams at the beginning of their existence, 

 just after the great permian deformation, occupying syn- 

 clines upon the carboniferous rocks. The permian topog- 



The Tin Ores of New South Wales and South Dakota. 

 The similarity of occurrence and of mineral aggrega- 

 tion of the tin ores of New South Wales and those of the 

 Black Hills, South Dakota, is worthy of mention. The 

 ores of both regions are extensively shown in the Mines 

 and Mining Building, Chicago Exposition, and it would 

 be difficult, if not imi^ossible, for an ordinary observer to 

 separate them according to locality if they should become 

 mingled. The ores of both places occur in veins of the 

 granitic type. "VVin. P. Bl-ike. 



ShuUsburg, Wis., Sept. ii, 1893. 



Horsford's Acid Phosphate 



Is the most effective and agreeable 

 remedy in existence for preventing 

 indigestion, and relieving those dis- 

 eases I arising from a disordered 

 stomach. 



Dr. 1?V^ 'W. Gardner, Spring- 

 field, Mass., says, "I value it as an excel- 

 lent preventative of indigestion, and a 

 pleasant acidulated drink when proper- 

 ly diluted with water, and sweetened." 



Descriptive pamphlet free on application to 



RuMFORD Chemical Works, Providence, R. 1. 



Beware of Subsi itutes and Imitations. 



For sale by all Druggists. 



[Free of charge to all, if of 

 Address N. D. C. Hodges, 

 York.] 



atisfactory character. 

 874 Broadway, New 



For Sale.— A collection of fossil Rhinocerob bones 

 (Aphelops fossiger Cope.) from the Loup Fork Ter- 

 tiary, including all the bones of one fore and one 

 hind leg, the pelvis, representative vertebrae and 

 ribs, and a nearly complete skull, with complete 

 lower jaws. All the bones of the limbs are perfect, 

 "rice §250. Address Dept. of Paleontology, Uni- 

 ersity of Kansas, Lawrence. 



For Exchange.— Books and pamphlets on geology, 

 ornithology, conchology, and entomology. State 

 what line and I will send list. I want Odonotafrom 

 any locality, a-d literature on this group. M. J. 

 Elrod, 111. Wes. Univ., Bloomington, 111. 



a rare chance to get a first-class microscopic- 

 )utfit write for full particulars to box 125, Sel- 

 lersville, Bucks Co., Pa. 



For sale or exchange.— A fine collection of Lep 

 idoptera, native and exotic. For particulars ad- 

 dress Addison Ellsworth, Binghamton, N. Y., care 

 Republican. 



For sale or exchange for works on entomostraca, 

 Wolle's "Desmids o£ the U.S.," Hentz "Spiders of 

 the U. S.," The Amer. Entomologist & Botanist, 

 Vol. 2, The Amer. Entomologist, Vol. i, Harris's 

 "Insects Injurious to Vegetation,'' colored plates, 

 copy formerly owned by Townend Glover. 

 r^_:.l~i,. iM — ..V, "■ .irr_ 



Dwight Marsh, Ripon, Wi 



"The Conchologist ; a Journal of Malacology," 

 Vols. I and 2, with wood cuts and plates, value 12 | - 

 will exchange for any works or pamphlets on Amer- 

 ican Slugs or Anatonry of American Fishes. W. E. 

 CoUinge, Mason College, Birmingham, England. 



Wants. 



U/ ANTED.— A copy of Mascart & Joubert's Le,=- 

 *' sons in Electricity and Magnetism, Vol. I. Ad- 

 dress R. W. Clawson, Vanderbilt University, Nash- 

 ville, Tennessee. 



PHEMIST.— Graduate of a polytechnical school, 

 and studied photographic chemistry in Ger- 

 many and Austria. Situation teaching or in ana- 

 lytical or experimental laboratory. M. B. Punnett, 

 Rochester, N. Y. 



yX/ANTED.- A recent college graduate to assist in 

 '* editorial work on Science. Those seeking 

 large emoluments need not apply. N. D. C. 

 Hodges, 874 Broadway, New York. 



A GRADUATE in medicine, experienced, will 

 ^ piepare or revise scientific and medical manu- 

 script for publication, read proof, compile bibliog- 

 raphies, &c. Will also consult New York libraries 

 [or persons out of town wishing references to rare 

 works. Address M. D., 104 ' Cambridge Place, 

 Brooklyn, N. Y. 



pOR SALE.— Volumes V. and VI. of the "Explor- 

 *■ ations for a Railroad Route from the Missis- 

 sippi River to the Pacific," 1S57, half calf, in good 

 condition; a large number of colored and uncolored 

 plates of Mammals, Birds, Fish, etc., etc. On 

 receipt of $7.00 will send to any ordinary point in 

 the U. S.. express paid. These volumes are now 

 rare. Address Dr. Shufeldt, Takoma Park, Dist; of 

 Columbia. 



AY'OUNG woman who has been an assistant for 

 a literary and scientific man desires a similar 

 position- Is an experienced and accurate stenog- 

 rapher and typewriter, thoroughly educated, and 

 sufficiently familiar with literary work to write, in- 

 dependent of dictation. Has ' some knowledge 

 of the Spanish language. Will gotoany part of the 

 United States. Address, Box 147, Ravenna, Ohio 



