WASHING MICROSCOPICAL SECTIONS. 57 



not only tedious but exposes the sections to considerable risk of 

 being contaminated with dust and other extraneous matter, I always 

 employ in its place a system of continuous washing. For this 

 purpose a small wide-necked bottle similar to those already 

 described will be required. Into the side of this, half an inch or 

 so below the bottom of the cork, a small hole about an eighth of an 

 inch in diameter must be drilled — any tinman will do this for two 

 or three pence. A well fitting cork being provided, this must be 

 pierced through the centre, so as to permit the stem of a small 

 funnel to pass through it. By means of small india-rubber tubing 

 (feeding bottle tube), the funnel stem is to be prolonged till it 

 reaches the bottom of the bottle on the side ichich is opposite to 

 that side containing the perforation. (See Fig. 2.) 



All being ready, half fill the bottle with filtered water, and put 

 the sections into it. Fit in the cork carrying the funnel, and after 

 having placed a disk of filtering paper into the funnel place this 

 beneath the water tap, and allow a gentle stream to trickle into it. 

 The water will pass to the bottom of the bottle, gradually ascend, 

 and then pass out at the hole in the side, by which means a constant 

 change in the water in the bottle is brought about and a system of 

 continuous washing established. As in bleaching, so in washing, 

 I generally let the apparatus do its work in the night. If the tap 

 be set a-running when one goes to bed, the washing will be found to 

 have been most effectually accomplished by the time one gets up in 

 the morning. 



