1146 Journal of Applied Microscopy 



only 10, or about 8 per cent., gave evidence of infection; while of the 600 

 cases, but 15, or 2.5 per cent., showed the presence of bacilli, and 10 of these 

 later gave evidence of having been previously exposed, thus greatly reducing the 

 percentage in the last experiment. It is generally estimated that diphtheria 

 bacilli are found in the mouths of about 18 per cent, of all healthy individuals. 

 The results above cited would indicate that this per cent, is very much too high. 



c. w. J. 



May, Richard. The Use of Orcein in the Dem- The sputum is thoroughly mixed with 

 onstration of Elastic Fibres in the Sputum. , ^ r i n 



Deut. Archiv. f. Khn. Med. 68: 427. ^n equal amount of 10 per cent, caustic 



potash solution, care being exercised 

 that no more heat is used than is needed to dissolve the sputum. When 

 thoroughly dissolved, centrifugalize and pour off the liquid portion. Add to the 

 sediment about 2 c. c. of Unna-Tanzer's orcein solution, the composition of which 

 is as follows : 



Orcein, 1.0 



Alcohol, absolute, 80.0 



Water, dist., 40.0 



HCl, cone, 40.0 



This solution has a red color, which changes to violet when the solution 

 comes in contact with the potash of the sediment. The original color is regained 

 by adding three to five drops of HCl. 



Place the centrifuge tube in boiling water for three to five minutes, as heat is 

 necessary to hasten the staining process. Hydrochloric acid alcohol is then 

 added, and after gently shaking the solution, it is centrifugalized by a few 

 turns of the machine ; the same process being repeated twice with fresh acid 

 alcohol. The formula for the hydrochloric acid alcohol decolorizing solution 



is as follows : 



Hydrochloric acid, cone, . . 5.0 



Alcohol, 95 per cent., . . . 1000.0 



Water, dist., 250.0 



Malkes, J. Estimation of Mercury in Urine. 599 c. c. of urine are mixed with 5 c. c. 

 Chem. Zeit. 35: 816, 1900. 



of egg albumm and 15 drops of acetic 



acid, and heated for fifteen minutes on the water bath. The mixture is poured 



into a beaker, allowed to settle, and the deposit collected in a filter. The paper 



and its contents are laid on a porous tile for a few minutes. The precipitate is 



removed to a small cylinder and covered with 50 c. c. strong HCl, a spiral of 



Cu being immersed in the liquid. After about fourteen hours all the Hg has 



amalgamated with the Cu, and the acid is dark in color. The wire is washed 



with water, alcohol, and ether, then dried, after which it is dropped into a tube 



5 mm. in diameter with a crystal of iodin, and heated until the sublimate of 



Hgl 2 appears on the wall of the tube. The amount of mercury is compared with 



that produced by a ring obtained in the same manner from a urine to which a 



known quantity of HgClg has been added. c. w. j. 



