70 PHARMACEUTICAL BACTERIOLOGY 



The essential requirements given under a, b, and c are obtained by 

 filtration, neutralization, and sterilization, as will be more fully explained. 

 Non-liquefiable solid media, as potato, bread, squash, etc., must be clean, 

 free from living microbes and other organisms, and there should be a 

 comparatively smooth exposed inoculating surface. These requirements 

 are attained by washing and otherwise cleansing, disinfecting, rinsing, 

 and heat sterilization (dry heat, steam or hot- water bath). 



PIG. 18. Arnold Steam and Hot-Air Sterilizer for Surgical Instruments. This 

 sterilizer is a combination and portable sterilizer, so designed that instruments may be 

 both sterilized and then dried by hot air, if desired. About 100 C. can be attained 

 with the hot air by simply turning the valve shown in the illustration, which turns the 

 steam as it escapes from the chamber into the base. 



The following are the more important media: 



A. Nutrient Bouillon. 



Beef Extract (Armour's, Liebig's, etc.), 3 gin. 



Peptone, 10 gm. 



Salt, 5 gm. 



Distilled Water, 1000 cc. 



Mix ingredients and boil for a few minutes. Filter through filter 

 paper. This bouillon may be modified by adding glycerin (6 per cent.), 

 and sugars, as dextrose, saccharose, or lactose (i per cent.). 



B. Loeffler's Blood Serum. Very largely used in making diagnostic 

 diphtheria bacillus cultures. In many cities this medium, with sterilized 

 cotton swabs, in sterilized test-tubes, is furnished free to physicians by 

 the board of health. In cities and towns where this is not done, the 

 pharmacist should be prepared to furnish the materials to the physicians. 

 The medium consists of 



Bouillon with i per cent. Glucose, i part. 



Blood Serum, 3 parts. 



The bouillon is prepared as above described, with i per cent, of glucose 

 added. The blood serum can be obtained from calf, sheep, ox, or cow, 

 through the butcher or at the abattoir. Collect the blood in a clean, 



