The Microscope. 345 



Their defects have usually been greater than their merits. But 

 if Spencer, Bausch & Lomb or Gundlach should take the sub- 

 ject in hand, something satisfactory would probably come of it. 

 Achromatic sub-stage condensers are beginning to be demanded 

 by advanced microscopists,aiid are beginning to be manufactured 

 in Europe ; why should we not be supplied with improved, ach- 

 romatic oculars ? They will be in request before long, and the 

 optician that first gets them into the market will reap the har- 

 vest and the honor. 



Messrs. J. W. Queen & Co. have just issued a catalogue in 

 English of the microscopes and objectives made by Reichert,of 

 Vienna. With this firm on one side of the continent, and Dr. 

 Edward Gray on the Pacific coast, microscopists that want any 

 of Reichert's lenses should be able to get them without delay. 

 His optical work equals the best. His semi-apochromatic, oil 

 immersion ji, 1.25 N. A., is a magnificent thing. 



Readers of The Microscope have fallen into the bad habit of 

 sending their Exchange notices on postal cards and tangled up 

 with blots, interlineations, compliments, complaints, sugges- 

 tions, requests and other items. These the Editor must trans- 

 late and copy for the printer. Henceforth, those that use that 

 Department, and cannot go to the slight trouble of writing 

 letters and Exchanges on separate sheets must suffer the loss. 

 Hereafter, all jjostal card Exchange notices will go into the 

 waste basket. The Editor's cat now has charge of that Depart- 

 ment, and she is utterly devoid of respect for anything except 

 her own rights. 



NENVS TRO/A 

 THE VVORKERS 



The pathogenic mouth-bacteria. — Dr. W. D. Miller is pub. 

 lishing in the Dental Cosmos a series of papers of great value 

 and importance to every scientific reader, and especially to 



