The Miceoscope. 1G5 



The difficulty of manipulating a 'section from half to three- 

 qiiai'ters of an inch in diameter, which in thickness is no greater 

 than the cells that compose it, need only be mentioned to be appar- 

 ent. This extreme tenacity is to be obtained of course only with 

 the most perfect preparation for cutting, both of the tissue itself 

 and of the knife and machine; but sections are now frequently cut 

 of a thickness averaging no more than double that of medium-sized 

 cellular elements. 



I need hardly state to you that for the successful mounting of 

 such sections when over one-quarter inch in diameter, the needle 

 and copper-lifter necessitate the utmost patience and delicacy of 

 touch on the part of the worker, whilst often even therewith a 

 choice section will be torn or mangled so as to lose half its value as 

 an exemplification of healthy or morbid structure. 



Excepting students and others ready to devote a large share of 

 time to microscopical work, it may be said that only those who have 

 labored perserveringly with these tools on really thin machine-cut 

 sections, appreciate the vexation and annoyance attending their use. 



These difficulties in the way of satisfactorily mounting such 

 specimens within a reasonable space of time, led me to make an 

 effort to secure some more facile means of manipulating sections than 

 the greasy copper-lifter and the ravaging needle. 



Perhaps the weightiest objection to copper or other metal in a 

 section-lifter is its property of rejecting water or glycerine, unless 

 just cleansed with alkali or ether. 



When mounting sections containing any fat — in reality a large 

 majority of all sections — the lifter soon becomes coated with a film 

 that causes water or glycerine to rise upon it in globules, which dis- 

 arrange the section and greatly hinder the worker. 



If instead of metal, however, we take some substance which in 

 its natural condition contains moisture, such, for instance, as hoi'n, we 

 at once avoid this difficu.lty. I therefore present to you a section-lifter 

 made of horn. It is in one flat piece, weighing ten grains, and is three 

 inches long and five-eighths of an inch in width at the blade, which is 

 square, of about ^^jy of an inch thick and merging into a handle 

 •one-twentieth of an inch thick, and three-eighths of an inch wide. 



The blade is smooth, flexible as paper and pierced with fine 

 holes. It can thus be easily insinuated beneath a section lying flat 

 on the bottom of a dish, and upon removal from the surrounding 

 fluid will allow it to drain away fi'om between the section and the 

 lifter. This brings the two into uniform apposition, which is the 

 great desideratum. The perforations also favor the floating of the 



