1895] MICEOSCOPICAL JOUKNAL. 355 



the measurement of the angle of microscopic objectives, 

 which was published in The Microscopical Journal, of 

 London, and in The Boston Journal of Chemistry. 



He died in Boston, November 17, 1883, and was buried 

 in Mount Auburn Cemetery. The sad news spread 

 rapidly, and three days later Dr. George E. Blackham, 

 of Dunkirk, N. Y., wrote the following beautiful eulogy 

 to an intimate friend of Tolles : " I have just heard in a 

 letter from Mr. Edward Bausch, of Rochester, of the 

 death of my good friend Tolles. I need hardly to say to 

 you how much this sad news has grieved me. The loss 

 to microscopy throughout the civilized world is simply 

 irreparable, but to those who had the happiness to be 

 counted among his personal friends, there is something 

 more than the mere eclipse of a great light in optical 

 science. His lofty character, his frankness, his honesty, 

 his modesty and dislike for anything that savored in the 

 least of boastfulness, his peculiar reserve and the warmth 

 of his friendship, when once the ice was broken, endeared 

 him to his friends as much as his marvelous genius and 

 unsurpassed skill in devising and constructing new optid*al 

 combinations distinguished him in the world of applied 

 optics. To the scientific world at large, he will live as 

 the man who dared to attempt what the accepted authori- 

 ties had declared to be impossible ; as the man who not 

 only dared to attempt, but succeeded in turning ^ the 180° 

 corner ' ; as the rare combination of artisan, artist and 

 scientist, whose work was not made to sell only, but who, 

 ever striving to surpass himself, wrought each new ob- 

 jective as if it were his only one, putting into each a por- 

 tion of his own individuality, and making a work of art 

 rather than an article of commerce. But to us who knew 

 him more intimately, he will live as the shy, reserved, but 

 warm-hearted man of genius. Standing at the very pin- 

 nacle of his profession, his death leaves a vacancy not 

 readily filled." 



