TECHNICAL APPENDIX. 179 



4. PRODUCTION OF SECTION PREPARATIONS. 



At the autopsy small pieces of the organs are 

 thrown at once into an abundance of absolute alcohol 

 and kept there two to three days, the alcohol being 

 renewed two to three times. In most cases the 

 organs are then ready for cutting. For this pur- 

 pose the firmer part of the kidneys, liver, and muscles 

 are placed on a piece of cork with liquefied commer- 

 cial gelatin * and then again placed, with the cork, in 

 absolute alcohol. At the end of twenty-four hours the 

 organ may be cut with the microtome. More delicate 

 organs must be embedded in celloidin or paraffin ; be- 

 fore staining, the paraffin is removed completely by 

 washing repeatedly in turpentine, or xylol and the 

 preparation is placed in absolute alcohol after re- 

 moval from the xylol. 



II. CULTURE OF BACTERIA. 



1. NUTRIENT MEDIA. 



A. Non-albuminous (according to C. Fraenkel and 

 Voges). 



Common salt 5 gm. 



Neutral commercial sodium phosphate 2 " 



Ammonium lactate 6 " 



Asparagin 4 " 



are dissolved in 1,000 gm. of distilled water. We may 



add ten per cent gelatin or one per cent agar, and 



thus obtain a non-saccharine nutrient medium which 



* One part of gelatin is dissolved in two parts of water. 



