1893.] MICROSCOPICAL JOURNAL. 257 



(n) To a inixturo of (a) and (h) add a irw dro{)S of a saturated 

 solution of ho'inatoxylin in absolute alcohol. 

 NO. 2. rK'JiO-CAKMINE. 



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

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

 acid in 24(1 c.c, of 92 per cent alcohol, and mix the two solu- 

 tions. 



NO. :{. BOKAX-CAKMINE. 



Dis.solve by means of heat 2.5 ])er cent of carmine in a 4 per 

 cent, aqueous solution of borax and add an equal portion of 

 70 per cent alcohol. 



NO. 4. GLYCEKINE-JELJ.Y. 



Soak 2 07,., of cut gelatine in 13 oz., of cam plior water, dissolve 

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

 cerine 16 oz., carbolic acid i oz. 



N. B. — For algie increase the proportion of glycerine. 



A Simple Home-Made Polariscope. 



Bv I. PIvRCY BLACKMAN, 

 SANDY HOOK, CONX. 



Make a pa{)er tube to fit thf draw tube of j^our microscope. 

 This can be done by gumming writing })aper and winding it 

 around a cylindrical stick of the pro[)er size. To this paper 

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

 The outside tulx; should be about 11 inches long and the inter- 

 nal tube about J 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, 

 al)out three dozen elliptical cover glasses. Insert one i)iece 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 precisel}^ the same way excejit the attachment to sup- 

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



