404 STAINS AND STAINING. 



at 45*^ to the tube, is placed rather more obliquely — viz., at an 

 angle of about 35" with the axis of the tube, or, what is the same 

 thing, at an inclination of 55"^ to the face of the eyeglass — the 

 light which it reflects will be completely polarised, so that it will 

 serve the purposes of analyser and drawing reflector combined. 

 The loss of light will thus be reduced to a minimum, and the only 

 modification necessary in the arrangement of the apparatus will be 

 that, in consequence of the increased inclination of the reflector, 

 the tube of the microscope, instead of being placed horizontally, 

 will have to be inclined to the horizon at an angle of about 20^ — 

 not altogether a disadvantageous arrangement in some respects. 



Staine ant) Staining. 



AFTER Mr. Squire had read his very interesting paper (see 

 p. 282 of our July part), in answer to questions he further 

 said : — 



In cutting his sections, the softer vegetable tissues were gener- 

 ally placed between the pieces of carrot in a section holder and 

 were cut in that position.. The harder pieces he surrounded with 

 paraffin, and all the animal sections were cut after freezing in 

 gum. Thinner sections could be got by embedding or saturating 

 in paraffin. All those wonderful serial sections obtained at 

 Cambridge had been cut by embedding or saturation in paraffin ; 

 but that took some little time to do, and for ordinary purposes it 

 was a shorter process just to freeze in gum and cut the sections 

 from material prepared in that way. 



With regard to a remark as to Schultze's solution being perfectly 

 insatiable for iodine, he was surprised at that ; for, as he had stated, 

 with the strength of the solution he used, only o'l of iodine would 

 dissolve in 70 cc. No doubt if it was very much more diluted it 

 would take up more iodine. 



All the sections shown were mounted in Canada balsam, 

 dissolved in benzole. He generally ran round them a ring of 

 caoutchouc cement, and found that it was very easy to mount 

 them in that way, and they did not break. As to whether 



