1893.] MICROSCOPICAL JOURNAL. 257 



(o) To a mixture of (a) and (b) add a few drops of a saturated 

 solution of ha?matoxylin in absolute alcohol. 

 NO. 2. nCRO-CARMINE. 

 Dissolve 1 gni., of carmine in 24 c. c, of liquid ammonia, .88, 

 and add 240 c.c, of distilled water. Dissolve 4 gms. of picric- 

 acid in 240 c.c, of 92 per cent alcohol, and mix the two solu- 

 tions. 



NO. 3. BORAX-CARMINE. 

 Dissolve by means of heat 2.5 per cent of carmine in a 4 per 

 cent aqueous solution of borax and add an equal portion of 

 70 per cent alcohol. 



NO. 4. GLYCERINE-JELLY. 



Soak 2 oz., of cut gelatine in 13 oz., of camphor water, dissolve 

 by means of heat, clarify with white of egg, filter and add gly- 

 cerine 16 oz., carbolic acid 1 oz. 



N. B. — For alga" increase the proportion of glycerine. 



A Simple Home-Made Polariscope. 



Bv I. PERCY BLACKMAN, 



SANDY HOOK, CONN. 



Make a paper tube to fit the draw tube of your microscope. 

 This can be done by gumming writing paper and winding it 

 around a cylindrical stick of the proper size. To this paper 

 tube is to be fitted a second tube that will slip inside of the tube. 

 The outside tube should be about II inches long and the inter- 

 nal tube about i inch shorter. Cut this internal tube diagonally 

 through the centre at an angle of about 35 degrees, as shown in 

 Figure 3. Procure from a dealer in supplies for microscopists, 

 about three dozen elliptical cover glasses. Insert one piece of 

 the inner tube, and sixteen of these cover glasses, and then put in 

 the other half of the tube, will hold the glasses in place between 

 the ends of the diagonally cut tube. This forms the analizer, and 

 is now ready for use. 



The cover glasses shoud be thoroughly cleaned before using, 

 and the paper tubes should be made dead black, inside and 

 outside. 



The part that goes below the stage is the polarizer, and is 

 made in precisely the same way except the attachment to sup- 

 port it in position for use under the stage. This, each one can 



