1894.] 3IICR0SC0PICAL JOURNAL. 277 



a permanent and honorable engagement, and if an en- 

 dowment could be raised by wliicli the offer of premiums 

 became a regular feature it would be a great stimulus to 

 advanced biologic work in this country. 



It is anticipated that the next meeting of the Ameri- 

 can Association for the Advancement of Science will be 

 held at San Francisco, California, next summer, and un- 

 der the present arrangement our Society may go there. 

 We shall, of course, have the benefit of all the special 

 rates that may be accorded, but to most of our members 

 it will appear a long journey. A very cordial invitation 

 in writing was received from the citizens of Chattanooga, 

 Tenn., through Dr. James E. Reeves, to meet there next 

 summer, and it will become the duty of the Executive 

 Committee to consider the matter in due season. 



Preparing Teeth for Microscopic Study. 



By W. E. CHRISTENSEN, D.D.S. 



When the tooth has been extracted, it must imme- 

 diately be brought into some conserving fluid — as alco- 

 hol or watery solution of bichloride of mercury — to pre- 

 vent the pulp from shrinking. Also, in all further ma- 

 nipulations as cutting, sawing, or grinding the sections, 

 careful attention must be given that the tooth or section 

 is at no moment without an excess of moisture. If teeth 

 of rabbits or dogs are used, it must be remembered that 

 the tissues of the pulp stick more to the wall of the pulp 

 chamber than in human teeth. This is important at the 

 first opening of the tooth. If human teeth are taken 

 from dead bodies, it must not be more than six hours 

 after death. 



In order to enable the preparing drugs to enter the 

 pulp, it is necessary to open the tooth and partially ex- 

 pose the pulp in such a manner that the pulp is not hurt. 

 J'or this purpose we make a section with a sharp, fine 



