340 THE AMERICAN MONTHLY [Dec, 



their enlargement, but after 33 years, evidence is brought to 

 light of a quiet worker, whose work would possibly divide our 

 admiration and wonder, could the specimens be juxtaposed for 

 inspection. The collection consists of sixty-five silver prints of 

 a uniform diameter of six inches each, mounted on a page of the 

 album, which is about twelve inches square. 



All of the negatives ofthese prints, must have been prepared 

 on wet, or collodion plates ; as the dry plate of to day, was not 

 known in 1860. The only information that the album gives in 

 relation to the work, is found traced on the negative with a 

 pin and reads Dr. Herapath's i inch lens, "Ross," April 25, 

 1860. 



After more than 30 years the silver prints are in a fair state of 

 distinctness, some are slightly faded, while others are perfectly 

 preserved. Another circumstance recalled is that they must 

 have been taken by sunlight, and in the daytime alone; both of 

 the methods alluded to are nov7 most generally superseded by 

 dry plates, lamp and electric light, and work mostly done at 

 night. Dr. Henderson rested from his earthly labors a number 

 of years ago, and before the era of the modern JVIicroscopical 

 Journal made it possible for workers to interchange or become 

 aware of each others varied lines of work, or to introduce them 

 to the mead of admiration that would have welcomed them in 

 the circle of ihe sciences. 



Dr. Henderson in every case wrote down the times magnified 

 as well as the number of diameters, a few characteristic speci- 

 mens of this rotation are given in the list herewith. 



LIST OF MICRO-PHOTOGRAPHS TRANSCRIBED FROM AN ALBUM OF 

 SILVER PRINTS PREPARED BY DR. HENDERSON, AT 

 MOBILE, ALA., ABOUT THE YEAR 1860. 

 Specimens derived from insect or parasitic life. 

 Leaf or scale insect (not named), 120. 

 Scales of Lepisma saccharina, 120. 

 Spiral vessels in stomach of house fly, 120. 

 Leg and claw of spider, 80. 



Spiracle of Dysticus margiualis (Water Beetle), 84. 

 Larva of the Breeze fly in egg, 120. 

 Acarus scabiei, or Itch mite, 230. 

 Trachea of Caterpillar, 80. 

 Foot of House fly, 120. 



