August 25, 1893.] 



SCIENCE. 



Ill 



Two localities in particular are associated respectively 

 with the freedom of the will and generalized space, and 

 whenever I think of one of these subjects the corresj)ond- 

 ing place, with surrounding buildings and scenery, is 

 always vividly present. Of course this is mere association 

 of ideas, but the localization of a numerical series is 

 doubtless nothing more, and I can see no analogy between 

 it and the phenomena of color-hearing, etc., which seem to 

 have for a basis an actual stimulation of two senses by the 

 causes that usually affect only one — probably a purely 

 ishysiological phenomenon. 



It is not necessary to suj^ftose any material basis for the 

 diagram. I used to think that mine arose from my learn- 

 ing my numbers from a set of blocks, which I jalaced in a 

 row. It seems just as likely, however, that the diagram 

 was wholly imagined, it being easier to remember the 

 numbers when associated with a position in sjaace. It 

 seems likely that many jjeojjle have these diagrams who 

 do not realize it; I was not always aware of mine till 

 they had been firmly fixed in my mind for many years. 



Akthub E. Bostwick. 



Office of The Standard Dictionary, 2 Clinton Hall, Aster Place, N. Y. Citj-, 



Round Worms in the Brains of Birds. 

 In reference to the note by Professor Gr. H. French, in 

 Science for June 2, it may be said that many years ago 

 the late Professor Nyman jjublished an article in the Pro- 

 ceedings of the Boston Society of Natural History on a 

 nematoid parasite which lives coiled up in the brain 

 of the anhinga or snake-bird in Florida. The species 

 is Eustrongylus jpapillosus of Diesing. Afterwards, in 

 the Bulletin or Report of Hayden's Geological Survey 

 of the Territories, the volume and year not in my mind at 

 this writing, I described and figured a similar species 

 {Eustrongylus huteonis) which was found by a student of 

 mine living under the eyes of Buteo sioainsoni, while an- 

 other species (Eustrongylus cliordeilis, Pack.) was removed 



from the brain of the night-hawk. These are all referred 

 to in my text book of Zoology, p. 1G9. A. S. Packard. 



Sharks in Fresh Water. 



I HAVE twice noticed extended and circumstantial ac- 

 counts of the existence, and in great abundance, of genu- 

 ine sharks in the fresh-water lake of Nicaragua. Though 

 the first account, according to my recollection, appeared 

 in a very reputable publication, I was inclined to think, 

 from the novelty of the idea, that it was merely an inven- 

 tion of some writer who was amusing himself, and fillin"- 

 out an article, but seeing another account by another 

 writer, and even more circumstantial than the first ac- 

 count, I cannot doubt that there is some basis for the 

 statement. If any readers of Science know of the occur- 

 rence of genuine sharks in fresh water, and especially in 

 the case of the lake above mentioned, I should be glad to 

 have a report to Science. 



In conversation the other day with one who is a good 

 deal of an authority in such matters, I found that he had 

 no knowledge of any occurrence of sharks in fresh water, 

 but saw nothing unreasonable in the idea. C. H. Ames. 



5 Somerset Street, Boston, Mass. 



The many friends of Henry de Varigny, Sc. D., 

 of Paris, France, will be glad to knowr that he is on the 

 way to this country, having sailed on Aug. 23, being 

 sent by the French government to investigate certain 

 questions connected with the fisheries and applied 

 entomology. 



— Corrections : In the letter by Joseph C. Thomson, 

 not Joseph W. Thompson, on page 97, for "innovated" 

 read "innervated." 



— Charles Scribner's Sons have just ready a little vol- 

 ume of "Stories of the Sea" to match the "Stories of the 

 South," "Stories of New York" and "Stories of the Eail- 

 way," already published. 



Horsford's Acid Phosphate 



Is the most effective and agreeable 

 remedy in existence for preventing 

 indigestion, and relieving those dis- 

 eases arising from a disordered 

 stomach. 



Dr. ^V. ^". 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 



Rum FORD Chemical Works, Providence, R. I. 



Beware of Substitutes and Imitations. 



For sale by all Druggists. 



Exchanges. 



[Free of charge to all, if of satisfactory character. 

 Address N. D. C. Hodges, 874 Broadway, New 



For exchange— Complete set of serial slides of em- 

 bryo chick, 12 to 72 hours old; of rabbit loin long, 

 and various stages of development of tadpole, 

 mouse and rat. Will sell or exchange for botani- 

 cal slides, or books or photographic apparatus. D. 

 T. MacDougal, University of Mmnesota, Minneapo- 

 lis, Minn. 



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 of the U.S.," Hentz "Spiders of 

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

 Vol. 2, The Amer. Entomologist, Vol. i, Harris" 

 "Insects Injtirious to Vegetation," colored plates, 

 copy formerly owned by Townend Glover. C. 

 Dwight Marsh, Ripon, Wis. 



"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. 

 Colliuge, Mason College, Birmingham, England. 



I wish to exchange a New Model Hall Tj'pe- 

 writer, price §30, for a Daylight Kodak, 4x5 prefer- 

 red. George A. Coleman, Dep't. Agric, Div. of 

 Ornithology, Washington, D. C. 



Exchange — The undersigned is desirous of ob- 

 taining correspondents interested in macro-lipidop- 

 tera, in Alaska, the far Western, Southwestern 

 and Southern States. Will also exchange rare 

 lepidoptera for entomological literature. Levi W. 

 Mengel, Reading, Penn. 



Wanted to exchange— Medical books. Obstetri- 

 cal Transactions, London, Works of Sir J. Y. 

 Simpson, Beck's Medical Jurisprudence. Hand- 

 book for the Physiological Laboratory, by Burnton, 

 Foster, Klein and Sanderson, Quain's Anatomy, 

 and about fifty others. Catalogues given. Want 

 Geological, Botanical and Microscopical books in 

 exchange. Dr. A. M. Edwards, 11 Washington St., 



Wants. 



T WOULD be grateful to receive replies to any of 

 ' the following questions.— Is copper found native 

 m Mexico ? Is it found native in Cuba ? If so, in 

 either or both cases can I purchase authentic speci- 

 mens ? Can any one furnish me with results of anal- 

 yses of native Mexican or Cuban copper, also anal- 

 yses of unalloyed copper reduced from the ore 

 from Cuba or Mexico ? Is it possible to procure 

 aboriginal implements of copper from Cuba or 

 Mexico ? Answers to these questions will greatly 

 aid the preparation of a report tor a scientific insti- 

 tution. C. B. Moore, 1321 Locust St., Philadelphia, 

 Pa. 



A YOUNG 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 go to any part of the 

 United IStates. Address, Box 147, Ravenna, Ohio. 



A GRADUATE of an American Polytechnic insti- 

 '^ tution and of a German University CGottingen), 

 seeks a position to teach chemistry in a college or 

 similar institution. Five years' experience in 

 teaching chemistry. Address Chemist, 757 Cary St. 

 Brockton, Mass. 



\A/ANTED.— A position as teacher of Biology, by 

 '• an experienced teacher, a college graduate 

 with four university post-graduate courses in the 

 Sciences. Good endorsements, and eighteen years' 

 experience. Address A. N. Somers, La Porte, Ind. 



WANTED.— Assistant in Nautical Almanac office, 

 Navy Department, The Civil Service Com- 

 mission will hold an examination on August 15 to 

 fill a vacancy in the position of assistant (computer) 

 in the Nautical Almanac office. The subjects will 

 be letter-writing, penmanship, trigonometry, rudi- 

 ments of analytical geometry and calculus, loga- 

 rithms, tlieory and practice of computations, and 

 astronomy. Each applicant mu.st provide himself 

 with a five-place logarithmic table. The examina- 

 tion will be held in Washington, and if applications 

 are filed in season, arrangements may be made for 

 examinations in the large cities. Blanks will be 

 lished upon application to the Commission at 



