ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 7.">9 



Society of Microscopists, says Jacob F. Henrici, was found in a lumber 

 room of the Harmony Society, a German community at Economy, 

 Pennsylvania (fig. 159). It contains, in a drawer at the base of the stand, 

 a Latin inscription, signed by Bernard Jussieu, setting forth that he 

 received the instrument from his very dear friend Linnaeus, as a gift of 

 friendship, in lasting memory of the pleasant intercourse which they 

 had at Paris in the month of August 1738. The Microscope is said by 

 the present aged members of the Harmony Society to have belonged 

 formerly to Frederick Rapp, one of the founders of the Society, who 

 came to America from Germany in 1804, and who died at Economy in 

 1834. He was a man of considerable culture, and much of the pro- 

 sperity of the community was due to his intellectual activity. No one 

 knows when or hosv the instrument came into his possession, or what 

 use he made of it. The body of the Microscope is of pasteboard, or 

 papier-mache, with wooden mountings, and fixed vertically on a wooden 

 stand. It is provided with a draw-tube, and the adjustment is by 

 means of a screw. Ten objectives accompany the instrument, each 

 consisting of a single lens, ranging in focal distance from about a 

 quarter of an inch to an inch. The lenses range in diameter from six 

 millimetres to a centimetre ; but when in position they are stopped 

 down by brass caps to an aperture of about two millimetres diameter. 

 Unfortunately one of the lenses of the eyepiece is lacking, and in order 

 to exhibit the power of the instrument, I have replaced ib for the 

 moment by a corresponding lens from my working Microscope. No 

 maker's name appears on any part of the instrument. The inscription, 

 in full, is as follows : — 



Audax lapeti genus 



Ignein fraude mala gentibus intulit 



Nil mortalibus arduum 



— Hor. Carm. Lib. i. 3. 



In perpetuara memoriam 

 cousuetudinis quam cum 

 dulcissimo suo sodali 

 Carolus Linne Parisiis 

 habebat boc ab eo araicitiae 

 donum accepit, mense 

 Augusto, MDCCXXXVIII 



Bernardus Jussieu. 



Aside from the interest attaching to this Microscope from its associa- 

 tion with two of the great scientific workers of the last century, it is 

 encouraging to compare our Microscopes of to-day with this crude 

 instrument, which Jussieu deemed worthy of the admiration expressed 

 in Horace's line, " Nil mortalibus arduum." 



Wilson Screw -Barrel Simple Microscope. — This instrument, 

 fig. 160, was kindly presented at the October Meeting by Major Meade 

 J. C. Dennis, who says that its date is about 1750, and that it belonged 

 to his great-grandfather. The Society has two other specimens of the 

 Wilson Screw-Barrel Microscope in its collection ; one bears the name 

 of Sterrop as maker, and the other, without a name, was presented to 

 the Society by Mr. C. dirties at the June Meeting, and will be found 

 figured and described in the Journal for October, pp. 636-7. 



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