206 The Microscope. 



may be made. {B.j With the Thoma or Schanze micro- 

 tomes, the tendency of the ribbon is to break during the process of 

 raising the block. This is obviated by the automatic rocking, and 

 other microtomes of this style. 



EDITORIAL. 



ARTIFICIAL LIGHT IN MICROSCOPICAL WORK. 



'' I ''HERE can be no dispute as to- the superiority of good natural 

 -*- light over artificial light for general microscopical work; but, 

 in addition to the unreliability of natural light, especially in the 

 cities, where, indeed, it is rarely utilized, the fact that most micro- 

 scopical work is done after dark, makes the subject of good artificial 

 light one of the greatest importance to the microscopist. 



Writers upon miscroscopical technology have not failed to rec- 

 ognize this, and they usually devote a short chapter to it, illustrated 

 by numerous more or less complicated and costly lamps. In makers' 

 catalogues, also, the same cuts are found and the lamps described. 

 In these efforts to put before the microscopical public attractive 

 apparatus, writers seem to have lose sight of the excellencies of the 

 humble hand lamp. Beginners are thus led to purchase the expens- 

 ive German student's lamp or some still more costly microscopical 

 lamp. It can safely be asserted that for the general purposes of the 

 working microscopist, a small'hand lamp giving a broad, flat flame, such 

 a lamp as can be bought anywhere for twenty -five or thirty cents, is 

 superior to any of the expensive lamps made especially for the pur- 

 pose, and we are convinced from our observation of the methods of 

 many microscopists that this is not realized by many except the 

 experts . 



By the size of the flame and the distance of the lamp from the 

 microscope, the intensity of the light can be readily adapted for any 

 work, from the use of the lowest powers to the examination of 

 histological and biological specimens with the highest immersion 

 lenses. For bacteriological work with the yV-inch or -jig^-inch 

 immersion lenses this light is unsurpassed In the examination of 

 opaque objects this lamp is not so convenient, as it is necessary then 

 to have the source of light at quite an elevation It is very easy, 

 however, to improvise a stand. 



For the examination of all sections by central light it is 

 best to place the lamp on the table directly in front of the micro- 



