THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



YOL. I. 



Kew York, Decembek, 1880. 



No. 12. 



Riddell's Binocular Microscopes: 

 An Historical Notice. 



BY SURGEON J. J. WOODWARD 



Bt. -Lieut. Colonel, U. S. Army. 



In April, 18Y9, a large binocular 

 microscope, made quarter of a cen- 

 tury before by the Grunow Brothers, 

 of Kew Haven, Connecticut, for Dr. 

 J. L. Riddell, then Professor of 

 Chemistry in the University of 

 Louisiana, was presented to the 



copist. It has excited considerable 

 interest among those who have ex- 

 mined it since that time, and I have 

 been requested to make it the sub- 

 ject of a brief notice, which I have 

 been the more readily induced to do, 

 because, although the proper merit 

 of Riddell as a discoverer in this 

 connection has been handsomely 

 acknowledged by such high Contin- 

 ental authorities as Harting and 

 Frey, and even by some English 



Fig. 32. — Arrangement of prisms above the objective in Riddell's first plan. 



Army Medical Museum by the wi- 

 dow of that distinguished micros- 



* P. Halting — Das Mikroskop, ( I cite the 

 2d German edition,) Braunschweig, 1866, 

 Bd. I, S. 194 ; see also Bd. III. S. 239 : 

 " Dem Nordamerikaner Professor Riddell 

 gebiihrt das Verdienst, zuerst den wahren Weg 

 angegeben zu haben, den man iiur Erreichung 

 dieses Zieles einzuschlagen hat." 



H. Frey — Das Mikroskop, 5te Auflage, 

 Leipzig, 1873, S. 32 : " Einem Amerikaner, 

 Riddell, verdankt man die Herstellung der 



writers,* it has been strangely ig- 

 nored by others, and even so fair, 



ersten Instrumente dieser Art;" i. e. truly 

 stereoscopic. 



Among the Englishmen, who have justly 

 accorded to Riddell the priority belonging to 

 him, I may mention with honor Samuel 

 Holmes — "The Isophotal Binocular Micros- 

 cope," English Mechanic and World of 

 Science, No. 800, July 23, 1880, p. 464 — 

 who, however, appears to have been unac- 

 quainted with Riddell's perfected instrument 

 as described in this paper. 



