1889.] MICEOSCOPICAL JOURNAL. 65 



Microscopical Laboratory Notes. 



By Prof. H. M. WHELPLEY, 



ST. LOUIS, MO. 



Read before the St. Louis Club of Microscopists at the January meeting. 



Cold Weather.— Do not permit the mounts to be reduced to the 

 freezing temperature. Even those preparations in liquids that do not 

 congeal at 32 F. will be injured by sudden or great changes in temper- 

 ature. 



Benzol is not Benzin, and microscopists should remember it, even 

 if some wholesale druggists do endeavor to sell benzin for benzol. I 

 have seen work spoiled and time and patience lost by those who tried 

 to use benzin for benzol. 



Handling Thin Animal Sections. — Those who are accustomed 

 to handling vegetable sections must remember when thev come to work 

 with animal specimens that the latter are much more liable to break 

 or tear than vegetable sections. If this is not borne in mind valuable 

 specimens will be ruined while handling them. 



Another Use for Benzol. — This liquid is a great solvent of oils 

 and grease. It will clean off the old grease that has been used to lubri- 

 cate a joint, and leave the surface bright and clean for a fresh applica- 

 tion of the lubricant. Benzol is very convenient for cleaning the spindle 

 to a turn-table when the table does not run smoothly. 



Spoiled Mounts are of no value, but the slides and cover glasses 

 are. When a mount spoils beyond repair place it in a wide-mouthed 

 bottle containing equal parts of alcohol, oil of turpentine, coal oil and 

 benzol. After a few days' maceration in this liquid, the slides and 

 cover glasses may be wiped clean, and are then just as good as new. 



Cover Glasses, as sold now a days, are quite clean. I wash them in 

 distilled water and keep them in a wide-mouthed bottle filled with al- 

 cohol acidulated with hydrochloric acid. They are readily cleaned with 

 tissue or Japanese napkin paper between the thumb and forefinger. 

 The patent devices for cleaning cover glasses are only serviceable to 

 make a show of those who use them. 



Hair-pin Clips. — Those who make many balsam mounts at a time 

 soon find that a number of clips are required to hold the cover glasses 

 in position until the balsam hardens. The clips in the market cost from 

 seventy-five cents per dozen upwards. I find it much cheaper and 

 just as convenient to make my own clips from ordinary hair-pins, as 

 proposed by Professor Wall. Such clips will cost about five cents per 

 dozen. 



To Handle Small Thin Sections. — A very convenient trowel for 

 this purpose is made by inserting the head of a large needle in a pen- 

 holder or other suitable handle ; then filing the needle flat on two op- 

 posite sides and breaking off the point. Such an instrument does not 

 take up as much fluid with a small specimen as the ordinary trowel 

 does. It also has other advantages over the customary methods of hand- 

 ling small thin sections of either animal or vegetable tissue. 



Glycerin Mounts that will Keep. — Glycerin is a very desirable 

 mounting medium for many purposes, and has but one drawback, and 

 that is its tendency to creep out of the cell. When mounting such sub- 

 stances as will admit of such a procedure, I overcome this difficulty bv 

 using less glycerin than is required to fill the cell. This should be placed 



