156 



THE AMERICAN MONTHLY 



[August, 



chinolin blue and weak alcoholic so- 

 lutidn of cyanin, when used with al- 

 kaline glycerin, make them a fine red, 

 while protoplasm stains blue and fat 

 bluish. The intensity of the dye de- 

 pends on the granules scattered 

 through the protoplasm. The nuclei 

 of the plasma cells remain colorless. 

 The granules are certainly not mole- 

 cularly fat. They consist of a mate- 

 rial having the following characters, 

 viz., it is insoluble in water, alcohol 

 and ether, and not attacked by alka- 

 lies, and does not readily decay. Fvu'- 

 ther than this is unknown. 



93. Sankey. On a new solution for 



staining sections of hardened 

 animal tissues. Qiiart. Jour. 

 Micr. Sci., 1876, p. 35. 

 Sankey uses an English dye com- 

 mercially known as anilin blue black, 

 easily soluble in water, not very solu- 

 ble in alcohol. To 1-2 cc. water add 

 0.5 gm. of the dye, and 99 cc. alco- 

 hol. This will stain in a few mo- 

 ments, and shows the nuclei better 

 than carmine. Excellent for the large 

 nerves. 



94. Bevan, Lewis. Preparation of 



sections of cerebral and cere- 

 bellar cortex for microscopic 

 examination. Quart. Journ. of 

 Micr. Sci., 1876, p. 69. Med. 

 Times and Gaz. 1876, Mar. 4. 

 Warmly recommends Sankey's 

 ' bkie black ' for nervous tissues and 

 prefers it decidedly before carmine in 

 aqueous solution of ^ to 1%. Espe- 

 cially does it bring out clearly the 

 prolongations of the cells, which may 

 be more clearly made out by washing 

 after staining and exposure for 20-30 

 minutes to a solution of chloral hy- 

 drate. 



(It will be found that success with 

 anilin dyes depends very much on the 

 quality of the article used. I have not 

 succeeded in obtaining good results in 

 nerve preparations with such dyes as 

 are found in the German market. 

 Treatment with chloral hydrate rend- 

 ers the sections unfit for preserva- 

 tion.) 



95. Luys. Emploi d'une nouvelle 

 matiere noire deriv^e de I'ani- 

 lin (noir Colin) , pour les pre- 

 parations histologiques et les re- 

 productions photographiques. 

 Gaz. Med. de Paris, 1876. 

 No. 29, p. 346. 

 Material hardened in chromic acid 

 or chrome salts must be very carefully 

 washed before treatment with this 

 new microscopical dye called ' Colin's 

 black.' The sections may lay 3-4 

 minutes in a ^-^f% solution, and may 

 then be mounted in the ordinary man- 

 ner. They are especially adapted for 

 photographic reproduction. 



Improved Microtome. 



The use of paraffin for imbedding 

 is attended with difficulties on ac- 

 count of its becoming loose in the 

 microtome. I have made a micro- 

 tome in which the difficulties are 

 overcome. A hole was turned about 

 half-way through the table of a micro- 

 tome, and into this a tube was screwed, 

 forming the well. The hole through 

 the remainder of the table, forming 

 the mouth of the well, was turned 

 with sufficient ' gather,' or taper, to 

 take up the shrinkage of the paraffin. 

 On the upper side of the piston a 

 dovetailed groove was turned. The 

 column of paraffin receives no sup- 

 port from the tube, but is securely 

 held by the piston at one end and by 

 the contracted mouth of the well-hole 

 at the other. The following dimen- 

 sions maybe of use if any one wishes 

 to make a similar instrument : Dia- 

 meter at the top, .9 inch, tapering 

 from diameter of .92 inch. Length of 

 taper, .15 inch. 



F. H. GowEN. 



— Dr. R. V. Ledenfeld has recently 

 described in Zoologischer Afizei'ger some 

 peculiar cells in certain Australian calca- 

 reous sponges which he regards as nerve- 

 cells. The nervous system of sponges, 

 when it consists of specially differentiated 

 cells, is mesodermal. It is concluded that 

 the calcareous sponges cannot longer be 

 regarded as protozoic organisms. 



