SCIENCE-GOSSIP. 



■Aniline oil may be used, and in this case it is not 

 necessary to dehydrate further than with recti- 

 fied spirit. The eosin is not entirely removed 

 unless one leaves the aniline on for a very long 

 time; two minutes is generally quite enough. 

 Aniline has the disadvantage of eventually 

 asserting its presence by a rather unpleasant 

 yellow colour in the resulting preparation. This 

 will be of small consequence if the radula is 

 thin and consequently there is little of the 



object in using a great deal of Canada-balsam, the 

 less the better, in reason. Do not forget to label. 



This process may seem tedious, but the results 

 make it worth doing. It occupies from first to 

 last about twenty minutes, and several specimens 

 may be made concurrently. I have tried with 

 some success a single stain made from violet 

 graph-ink, a substance whose exact composition 

 it may not be safe (scientifically) to state with 

 more exactitude. This is quite useless for certain 



■jpajyp « 



Odomtophorbs "i Moi i 



Hyalinia ctUaria (srcond row); fig. i, Hyalinia alliaria (second row) ; li«. 3, 

 ; // yaiitiia nitidula. 



mounting medium used, but for the larger objects 

 the cedar -oil process is to be recommended. Oil 

 of cedar does not attack cos in (6) Finally, having 

 taken care that there are no bubbles in the pre 

 paration. and having arranged the end of the 

 radula in its permanent position, dry off as much 

 of the clearing agent as possil/1 [arette 



paper Wll may flatten out the radula 



a little with the pa[ I 



Canada- bal sam (preferably in xylol) on the objet I, 

 and gently let down ll ere is no 



species, though it gives good results in others. Its 

 permanence may also be suspected. If one is in 

 a great hurry, and does not want a preparation 

 that will last, one cannot do better than with 

 methylene blue. Methyl green is also very good, 

 and so is safranin, occasionally. Another fairly 

 good but uncertain stain is Nicholson's blue. I 

 have preparations (in balsam) done with this 

 ll b have lasted perfectly well foi 1 l| hi 

 months, and show no iding . but ii i ■ a 



rough-and-ready method Thi colour in methyl 



