Production of Sections 279 



quickly done, although difficult to describe exactly. The 

 sections will often stick to the slide without the aid of the 

 Mayer's albumen, simply by the drying of the water alone. 

 To make doubly sure, it is as well to combine the processes, 

 especially should the cut material be deficient in albuminous 

 matters, or if that substance has been over-coagulated in 

 the process of fixing. 



Finishing Ribbon Sections. Glass slips and covers are 

 readily cleaned by immersion for a day in strong sulphuric 

 acid ; they should be put in singly. Subsequent washing 

 for a few hours in running water will rid them of all trace 

 of acid ; then they are stored in 90 per cent, alcohol until 

 required for immediate use. When sections that have been 

 stuck to a slide are to be finished off, the paraffin is removed 

 by placing the slide upon a hot bench for a few moments 

 until the wax is just melted, when it is blown to one end of 

 the slide and wiped off. The hot slide is at once placed in 

 pure xylol to rid it of the remaining paraffin. From the 

 xylol it is transferred to 90 per cent, alcohol for a short time 

 to rid it of the liquid hydrocarbon and to coagulate the 

 Mayer's albumen, insuring thus the adhesion of the sections 

 to the slide during the subsequent operations. The xylol 

 may be used many times over until it becomes saturated 

 with paraffin, in which case the first alcohol bath from xylol 

 should consist of hot alcohol say, about 40 C., in order 

 to rid the sections thoroughly of any paraffin that may 

 be brought away from the paraffin-saturated xylol. The 

 passing of the mounted sections through the various fluids 

 previous to the final inclusion in Canada balsam is most 

 readily accomplished by means of grooved porcelain troughs 

 made with five grooves, and holding ten slides, if pairs are 

 placed back to back. At least nine of these troughs should 

 be procured, and fluids kept in them as follows : 



Xylol ; 90 per cent, hot alcohol, then through diminish- 

 ing strengths of alcohol 90 per cent., 70 per cent., 50 per 

 cent., 30 per cent, and finally distilled water; two troughs 

 remain for the staining processes. A plain glass cover 



