1895.J MICROSCOPICAL JOURNAL. 261 



tain are spermatozoa (fig. 12); tubercle bacillus (fig. 6, c); 

 urates; mold (fig. 6, e) ; crystals of uric acid (fig. 6, f) ; 

 yeast (fig. 6, d) ; oxalate of lime (fig. 13) ; stellate crys- 

 tals of triple phosphate (fig. 15) ; ammonia magnesium 

 phosphate (fig. 14); acid ammonium urate (fig. 16) ; cys- 

 tin (fig. 17) ; hippuric acid (fig. 18) ; leucine (fig. 19) ; 

 tyrosin (fig. 20) ; and acid sodic urate in cylinder (fig, 

 11). 



We are indebted to " Medical Microscopy," by J. E. 

 Reeves, M. D., for the information and illustrations con- 

 tained in this article. 



Microscopical Technique Applied to Histology. — X. 



[FROM THE FRENCH OE RENE BONEVAI,.] 



{Continued from page 239, August 1895.) 

 The Lungs. 



The endothelium of the air cells may readily be seen 

 in the lungs of a recently killed animal. 



1. Select the frog. In this exceedingly simple lung 

 the arrangement of the epithelial cells may be seen in 

 all their simplicity. Open the abdominal cavity after 

 cutting the medulla oblongata ; by a pipette in the glot- 

 tis inject into the lungs a 1 to 300 solution of silver ni- 

 trate. Close the pipette with the finger to keep the 

 lungs distended, and expose to the sun. When the 

 lungs are colored brown, remove them and slit them 

 open under water. Stain the nuclei of the endothelial 

 cells with alum carmine, carefully extend the lung on a 

 slide, inner face upward, and partly dry by the method 

 already described. Dehydrate in absolute alcohol with 

 many renewals ; clear with oil of bergamot and mount 

 in balsam. 



2. A slight modification of this method is needed for 

 the endothelium of the lungs of mammals. Open the 



