Twenty-fourth Annual Meeting. 



23 



mented by certain physiological tests. These latter points are now out of the ques- 

 tion, for the limited time we have had to work, ^ye have, however, a very few crys- 

 tals of the substance here to present, promising to follow the investigation further 

 as time permits. 



AX INEXPENSIVE EEAGENT BOTTLE, OF SERVICE IN MICROSCOPIC 



WORK. 



BY PEOF. E. B. KNEER, MIDLAND COLLEGE, ATCHISON. 



A very convenient reagent bottle, of service in pre- 

 paring mounts for the microscope, may be made in a few 

 minutes from an ordinary wide-mouth, half-ounce or ounce 

 bottle, a short piece of glass tubing, a bit of rubber tub- 

 ing, and an ordinary wood cork to fit the bottle. 



Having selected a piece of glass tubing about one- 

 fourth inch in diameter and two feet long, soften it in a 

 flame and draw out to a narrow contraction at intervals 

 of about four inches, then cut ofif the sections with a file. 

 After about six of these have been made, again cut each 

 one through the middle with a file, and round off the 

 sharp edges of, both ends by holding in the flame a few 

 seconds, taking care, however, not to allow the smaller 

 end to close up. In this way enough tubes for a dozen 

 bottles can be made in a few minutes. Next select corks 

 to fit the bottles, and with a cork borer make a hole 

 through the middle of each of proper size to admit one 

 of the glass tubes and hold it firmly. Pass the tubes 

 (each being somewhat over two inches long) through the 

 corks until, when placed in the bottles, the narrow end j-m j 



will almost reach the bottom. This will leave about three- 

 eighths of an inch of the wide end of the tube extending above the cork. Over this 

 protruding portion pass about li inches of rubber tubing one-fourth inch in diam- 

 eter. Now close the open end of the tube by about one-fourth inch of the core that 

 was removed from the cork in making the perforation, and the bottle is complete. 

 I find it very convenient to have a dozen or more, one for each fluid employed in 

 working about the microscope. These bottles are very inexpensive, the whole dozen 

 costing not morethan a single one of the glass-stoppered, glass-covered dro^jping 

 bottles, and they work more satisfactorily. 



In use, the rubber tube above the cork is first compressed, then the pressure re- 

 laxed, thus filling the glass tube with liquid. Cork and tube are now removed to- 

 gether from the bottle, and as much of the liquid as is desired is delivered just where 

 wanted on the glass slip by again compressing the rubber. The cork and tube are 

 now returned to the proper bottle, where they will be in readiness when again 

 wanted, meanwhile serving as a stopper to exclude dust or moisture as effectually as 

 any glass cover ever devised. 



This simple device was first described by the author in The Microscope for April, 

 1891, but he again presents it, hoping that it may prove as convenient to others as 

 it has to himself. 



