1 8 BACTERIOLOGY. 



For drawing macroscopical appearances, and for 

 illustrating microscopical specimens with or without 

 the use of a camera lucida, the following materials 

 should be within reach : 



Pencils. 

 Etching Pens. 

 Prepared Indian Ink. 

 Water-colour Paints, and Brushes. 

 Ordinary and tinted drawing paper and other usual 

 accessories. 



Micro-Photographic Apparatus. The appa- 

 ratus of Zeiss was recommended to the author by 

 Professor Koch. A large horizontal pattern may also 

 be obtained from Seibert and Krafft, of Wetzlar, 

 but as very little more is required than a flat board, 

 fitted with an ordinary wooden camera, and pro- 

 vided with clamps for fixing the microscope, it is 

 more economical to devise one's own apparatus. 

 The best results are obtained by employing the 

 electric light; and specimens are preferably stained 

 with bismarck brown, vesuvin, or chrysoidin. For 

 mounting the preparations Koch recommends a 

 saturated solution of acetate of potash ; but there 

 is little or no objection to the use of Canada 

 balsam. Dr. Hauser's micro - photographs of 

 specimens stained with bismarck brown and 

 mounted in Canada balsam dissolved in xylol, are 

 the most beautiful results hitherto obtained.* 



* Hauser, Uber Faulniss Bacterien und deren Bezichungen zur 

 Sefiticam ie. 1885. 



