42 



THE AMERICAN MONTHLY 



[March, 



found useful by histologists and others 

 who are in the habit of using staining- 

 fluids. 



It is a matter of eveiy-day experi- 

 ence with those who employ the mi- 

 croscope in histological research, that 

 however careful they may be to filter 

 their reagents before beginning the 

 day's work, particles of foreign matter 

 are apt to appear ere long in the vari- 

 ous solutions employed, and, not un- 

 frequently, become attached to the 

 most interesting portions of valuable 

 preparations, marring their beauty, 

 and sometimes detracting from their 



Fig. io. — B'lLTERiNG Wash-Bottle. 



value. The usual forms of filters 

 of paper and cotton, are not as con- 

 venient as one could wish, and ,it was 

 with a view to the production of a 

 simple apparatus, which would deliver, 

 perfectly filtered, any quantity of a 

 staining-fluid, or other reagent, from 

 a single drop to a dishful, that I de- 

 vised, about two years ago, the bottle 

 here described. A wide-mouth bottle, 

 of convenient size, is fitted with a cork 

 through which three glass-tubes are 

 passed; one of which (fig, lo, a) 

 reaches nearly to the bottom of the 

 bottle, while the other two tubes ex- 

 tend only just below the cork. 



The long tube is curved above the 

 cork, and at a point just beyond the 

 curve, there is attached to it a short 

 piece of tubing (J)) of twice the diameter 

 of the first. The lower end of this 

 larger tube (at d) is also fitted with 

 a cork, through which passes a short 

 piece ot small tubing, which is slightly 

 contracted at its distal end. Over the 

 cork and open end of this short deliv- 

 ery tube, a piece of fine muslin {d) is 

 stretched, and the space ib) in the 

 large tube, is filled with a loosely 

 packed plug of absorbent cotton, form- 

 ing a very effectual filter. 'J'he second 

 tube ends above the cork in a "thistle- 

 bulb " funnel {e), the opening in which, 

 is formed into a neck of sufficient 

 length to enable one to cork it securely. 

 Through this thistle-top tube the re- 

 agent may be readily poured from a 

 dish or other vessel. The third tube 

 {g) is bent over the side of the bottle 

 and a piece of rubber-tubing is at- 

 tached, which may end either in a 

 short glass mouth-piece or an atomizer- 

 bulb, as the student mav elect. In 

 case the bulb is used it will be found 

 necessary to loosen the cork in the 

 funnel-tube {e) when a sufficient 

 quantity of the contents has been ex- 

 pelled, in order to release the pressure 

 and stop the flow. 



This bottle differs from the one de- 

 scribed at Montreal, only in the use 

 of the thistle-top tube, and common 

 bottle, in place of the more expensive 

 three-neck or Wolfe's-bottle. The 

 thistle top tubes may be purchased 

 for about fifteen cents apiece, while 

 the Wolfe's bottle would cost fifty 

 cents or more. 



Further, the thistle-funnel permits 

 a solution to be readily poured into 

 it from a dish while the necks of the. 

 Wolfe's-bottle are so small that the use 

 of a funnel is necessary, except when 

 the solution is poured from a spout or 

 bottle-neck. Stains may thus be re- 

 turned to the bottle and used over 

 and over again, being perfectly filtered 

 each time they pass through the plug 

 of cotton. A gentle breath at the 

 mouth-piece, or a slight compression 



