156 THE AMERICAN MONTHLY [July, 



The Student Microtome. 



By BAUSCII & LOME, 



ROCHESTEK, N. Y, 



This useful piece of apparatus is sliown in the frontispiece of the 

 June number. On account of the character of the work done on these 

 instruments, hicqucred brass is not suited to them. They are made of 

 iron, as far as practical, nicely finished by japanning, while brass is 

 used for the delicate parts, and highly polished and nickel-plated. 



The base, curved arm, upright and V-shaped beds are made of one 

 continuous casting, thus insuring rigidity without excessive weight. 

 The knife carrying-block is fitted in the angular way in such a manner 

 that the knife moves steadily through it without deviating from its 

 plane and without requiring any extra pressure. Stop-screws with 

 soft rubber cushions are fastened at the ends of the way, which serve 

 to overcome any sudden concussion, and thus prevent a vibration of 

 the knife. The upper surface of the block is provided on its entire 

 length with a grooved slot, to which is fitted a sliding tlnmib-screw, so 

 that the knife may be fastened at any point upon it. 



To the carriage are directly fitted the micrometer screw with grad- 

 uated disk and a slide which is acted upon by the former. A pro- 

 vision is made for taking up the possible wear on the screw. At one 

 side of the carriage a spring is attached which works in the grooves on 

 the edge of the disk with a pronounced click, so that the feed may be 

 controlled without watching it ; this may bq loosened so that it will not 

 act wdien it is desired to use the index only. A nickel- plated drip-pan 

 is countersunk in the upper surface of the bed, and is easily removable 

 for the purpose of cleaning. 



The feed-screw attachment is placed at one end of the bed, and for 

 all ordinary work the best position of clamp is as shown in the cut. 

 For serial sections it may be swung on its axis to the middle of the bed 

 and fastened in this position. 



The dimensions are as follows : 



Length of bed, 6 inches. 



Total height, ....-- 4 



Limit of adjustment by micrometer screw. 



Limit of adjustment by clamp, - - - i 



Diameter of graduated disk, - - - - 1^ 



Pitch of screw, _..--- -^i- 



Length of cutting edge of knife, - - - 3+ 



1 



The Mississippi Valley Medical Association will hold its r6th 

 annual session at Louisville, Ky., Oct. 8, 9, 10, 1890. The medical 

 profession is cordially invited to attend, and papers are earnestly solic- 

 ited. Titles should be sent to the secretary, Dr. E. S. McKee, 57 W. 

 7th St., Cincinnati. The social and intellectual features of the occa- 

 sion promise to be very great. An additional feature will be the an- 

 nual session of the American Rhinological Association, which convenes 

 at the same place Oct. 6, 7, 8, 1S90. The secretary is Dr. R. S. 

 Knode, Omaha, Nebraska, who will be glad to receive tides of papers. 



