1892.] 



MICROSCOPICAL JOURNAL. 

 MICROSCOPICAL APPARATUS. 



89 



Camera for Micro-photography.— We are indebted to a writer 



in Science- Gossips Mr. D. W. 

 Barker, for a description of his 

 *' home-made" apparatus shown 

 in the figure. 



A wooden table is made some- 

 what wider around its top than 

 the front of the camera, and con- 

 tains near the centre an aperture 

 through which to project slightly 

 the microscope tube. After re- 

 moving the lens from the camera, 

 place the latter on the table with 

 its front downward. Place the 

 microscope underneath and close 

 the aperture to rays of light by 

 means of the small silk sleeve a. 

 A good lamp is to be used for il- 

 luminating. Focus roughly by 

 hand, and then finely on to the 

 ground glass of the camera, by 

 means of the fine adjustment screw 

 h. Use a large diaphragm on the 

 microscope base. Expose in the 

 ordinary way. A little practice will soon show the right exposure to 

 be given, always using the same lamp. A small beading round the top 

 of the table holds the camera firmly. 



A nice sterilizer. — In all bacteriolog- 

 ical work, sterilization or the destruction 

 of all germs in apparatus used is absolutely 

 necessary. Dry heat is often employed. 

 Koch invented a steam-chest, the descrip- 

 tion of which may be found in Ball's 

 " Essentials of Bacteriology." In this 

 country there is a steam-cooker made of 

 copper, which is sold for cooking meat and 

 vegetables, but which has been found to 

 make a nice sterilizer. The accompany- 

 ing figure presents a good idea of it. It 

 may be heated by the Bunsen burner or 

 upon a stove. With the single Bunsen a 

 temperature of 312" F. (100° C.) may lie 

 obtained in from 6 to 10 minutes. 



A is the reservoir containing cold water 

 which passing through the openings 

 reaches the boiler B, where owing to 

 its shallowness the water becomes hot 

 very rapidly. As fast as the steam forms 

 it rises thro\igh the aperture C and passes 

 > into tlie chamber D, completely envelop 



