344 SUilMAKY OF CUHREXT RESEARCHES RELATING TO 



bubbles from microscopical preparations. As the superficial viscosity of 

 ether is very feeble, aud its tension less than that of alcohol, it should be 

 preferable for the purpose to the latter, though it must be borne in mind 

 that ether is not miscible with water, like alcohol, in all proportions. But, 

 as a matter of fact, experience shows that ether does cause to disappear, just 

 as alcohol does, the air-bubbles adhering to organic tissues. 



Kronig's Cement.* — Dr. Krouig calls attention to the convenience of a 

 sealing cement composed of two jiarts of was and seven to nine parts of 

 colophonium. The colojjhonium is added piecemeal to the melted wax, 

 the result is filtered, and the mass left to cool. Solid at ordinary tempera- 

 tures, it is readily melted by placing the containing vessel in hot water. 

 As it hardens rapidly, the jireparation can be finished at once. It is 

 insoluble in water, glycerin, and caustic potash ; its consistence is good ; 

 its composition is cheap and simple. 



Aylward's (H, P.) Opaque Wood Slide. 



[" Parallel-sided, sunk cell, beyond which is a parallel-sided groove to hold a 

 brass-flanged ring. The object is put into the cell, a thin cover-glass laid on 

 the top of it, and the brass ring dropped into position holds all perfectly secure, 

 and if pressed tightly down, we believe, air-tight also. The special qualifica- 

 tions Mr. Aylward claims for this slide are its simplicity, and also that owing 

 to the dryness of the wood botanical objects need not be thoroughly diied before 

 mounting. The wood will absorb all dampness that may be left, and in so 

 gradual a manner that all shrinking or curling of the specimen will be 

 avoided."] 



ScienUf. Enquirer, II. (18S7) p. 39. 

 Gage. S. H. — Centering Card. 



[The card is prepared by making upon it several concentric circles, and then 

 cementing to it pieces of glass or Bristol board, so that when the slide is 

 placed in position the centre will be over the centre of the circles.] 



The Microscope, VI. (1SS6) pp. 266-7 (1 fig.). 

 GcABDiA, J. — Hints for Microscopists. 



[To view preparations from both sides with high powers : — Two thin strips of 

 wood, brass, cardboard, &c., 3 in. x 1^ in. From the centre of one cut out a 

 square 3/4 in. side, and from the other a square slightly larger than 7/8 in. 

 side. Glue the two strips together, and there is a ledge 1/16 in. for the pre- 

 parations to rest on. The specimens are mounted between two 7/S in. cover- 

 glasses and put in the frame or carrier.] 



En^L Jilech., XI-V. (1887) p. 11. 



HErKCK, H. VAX. — Nouvelle preparation du Medium a haut indice (2*4) et note sur 



le liquidambar. (Xew preparation of the mt dium of hi^h index (2 • i). and note on 



liquidarabar. [Post.'] B'lI. Soc. Bchj. .1/ic;-., XIII. (1SS6) pp. 20-4. 



Morris. W.— Notes on experiments in mounting the AmpMpleTura pellucida in media 



having a higher refractive index than Canada balsam, [f'o^^.] 



Jouni. and Froc. B. S'.>c. X. S. Wales, XIX. (ISSO) pp. 121-33. 

 V R I E s, H. D E. — Over het bewaren van plantendeelen in spiritus. (On the preserva- 

 tion of parts of plants in spirit.) [_Post.'] MaaM. t. Natuurwet., 1886, No. 5. 



(6) Miscellaneous. 



Two new Sugar Reactions. f — Dr. H. Molisch found that sugar solu- 

 tions, with the exception of inosite, immediately assume a deep violet 

 colour on the addition of some drops of a 15-20 per cent, a naphthol 

 solution and sulphuric acid in excess, and that the addition of water then 

 produced a deep violet precipitate. If thymol be added to the a naphthol 

 the colour becomes a bright ruby red, and the precipitate, from water, is 

 carmine red. In this way • 00001 per cent, of sugar can be demonstrated. 

 Carbohydrates and glucosides also give these reactions, but more slowly, 

 and after the action of sulphuric acid. 



♦ Arch. f. Mikr. Anat., xxvii. (1886) pp. 657-8. 



t ^B. K. Akad. Wise. Witu, xcii. (1886) pp. 012-23. 



