THE MICROSCOPE. 123 



and to fear dangerous adulteration, in almost every article of the 

 grocery kind." — Ex. 



A New Method of Bleaciiing and Washing Sections. — 

 Microscopists are indebted to Sylvester Marsh for the following ex- 

 cellent process, the description of which first appeared in the Eng- 

 iish Mechanic : 



Two wide-mouthed bottles, each of about two ounces capacity, 

 are procured. Corks are fitted to them, and the corks are connected 

 by a short piece of glass tubing which is bent at each end, and 

 passes down through the corks, passing just through one cork and 

 far enough through the other so as to almost touch the bottom of 

 the bottle when the cork is inserted. A channel is to be made in 

 the side of the cork carrying the long arm of the tube, and one of 

 the bottles is then filled about three quarters full of filtered rain-water, 

 and in this the sections to be bleached are placed. In the other 

 bottle a sufficient quantity of chlorate of potash in crystals is placed 

 to just cover the bottom, and then a drachm or so of strong hydro- 

 chloric acid is poured upon them. The corks are then placed in the 

 bottles, being particular to put the cork carrying the long arm of the 

 tube in the bottle containing the sections. The yellow vapor of 

 chlorine (or, rather, of euchlorine), immediately begins to be evolved, 

 and passes over through the tube into the water containing the sec- 

 tions. When the v.ater becomes saturated with chlorine, the excess 

 rises and escapes through a channel in the cork. It is Mr. Marsh's 

 practice to arrange the apparatus for work at night, and to set it out 

 of doors in a covered place, in order to avoid annoyance from the 

 escaping fumes of chlorine. 



To wash the sections after bleaching, a bottle is taken, similar 

 to the others, but having a small aperture filed in the side at the 

 shoulder. The bleached sections are placed in the bottle and cov- 

 ered with filtered water. A small funnel is then fitted to the cork, 

 and the neck of the funnel is continued to the bottom of the bottle 

 by a piece of fine rubber tubing, the tube being carried to the side 

 of the bottle opposite the aperture. A sheet of filtering paper be- 

 ing placed in the funnel, the bottle is placed beneath a water tap, 

 and a gentle stream of water allowed to trickle into the funnel con- 

 tinuously. A constant circulation of water is thus maintained in the 

 bottle, the discharge being through the orifice in the side. As in 



