222 THE AMERICAN MONTHLY [Jidy, 



practice attended by danger on account of possible contamina- 

 tion b}'' pathogenic organisms. The boiling of milk, even for a 

 moment, would probably be sufficient to remove the very dan- 

 gerous quality of tuberculous milk. We note that your Mag- 

 esty's gracious commands do not extend to inquiry or report on 

 adminstrative procedures available for reducing the amount of 

 tuberculous material in the food supplied by animals to man, 

 and we have regarded such questions as being beyond our prov- 

 ince. — Sir George Buchanan, Prof. G. T. Brown, Dr. G. F. Payne, 

 Prof. Berdon Sanderson. 



MICROSCOPICAL MANIPULATION. 



To Photograph Vertically. — Mr. Leslie of Barrackpore, 

 India, mounts his microscope in a vertical position on a base 

 board and adjusts it as for ordinary use. On each side of the 

 instrument are uprights, between which slides a small box about 

 six inches square and four or five deep. It works up and down 

 in slots cut through the two uprights, to which the box can be 

 fixed firmly above the microscope by set screws on either side. 

 At the bottom of the box is an apparatus considerably larger 

 than the tube, and around this aperture is a sleeve made of 

 black cloth, or silk, which hangs down vertically from the box 

 and is fastened round the tube. At the top of the small box 

 grooves are cut as in a camera, to insert the ground-glass frame 

 and the dark slide. 



The mirrow of the instrument is now adjusted so as to illumin- 

 ate the object (on the stage). The source of illumination may 

 be daylight or lamp light. The ground glass frame is now in- 

 serted in the box which is either raised or lowered till the proper 

 sized disc of light is obtained in the ground glass. The object 

 is now focused by means of the coarse and fine adjustments of 

 the microscope which are under full control of the operator. 



The microscope is now mooved if necessary on the baseboard 

 till the disc is in a proper position on the ground glass. In 

 front of the mirror of the microscope is a blackened cardboard 

 shutter, which is attached to one of the uprights, in order to cut 

 off the light from the mirror. When the proper focus has been 

 secured, this cardboard shutter is lowered and the light cut off 



