MEDICINAL SUBSTANCES 197 



In spite of shell and of egg menabrane, the egg is gradually 

 contaminated more and more, until finally complete decomposi- 

 tion has taken place. Tests made by European investigators 

 show that fresh eggs inoculated with various molds resist penetra- 

 tion completely for about i month. After 8 weeks species 

 of Cladosporum had entered. In 12 weeks Phytopthora in- 

 festans developed and still later Rhizopus nigricans. Other fungi 

 which finally developed in the interior of the eggs were Clado- 

 sporum herbarum, Aspergillus niger, Penicillium glaucum and 

 some yeasts. Fresh egg albumen is said to have marked bac- 

 teriolytic properties, but such properties are certainly quickly 

 lost upon exposure to the air and light. Some eight or more 

 species and varieties of bacteria are concerned in the decomposi- 

 tion of eggs, principally aerobes. Some of these liberate sul- 

 phuretted hydrogen {Bacillus oogenes hydrosulphureus group); 

 others belong to the B. coli group and still others cause decomposi- 

 tion of the white without any pronounced color development. 

 Liquefaction of the white as well as of the yolk is the most marked 

 physical change in eggs undergoing bacterial decomposition. 

 Mold infection is very generally indicated by an odor of mus- 

 tiness. Pronounced mold infection is further indicated by spots 

 shown in candling. 



19. The Bacteriological Examination of Pharmaceutical Preparations 



Thus far practically nothing has been done as to the bac- 

 teriological examination and standardization of medicinal sub- 

 stances. There is a popular behef that the ordinary pharmaceu- 

 ticals, particularly the tinctures and the fluidextracts, are quite 

 free from bacteria, the supposition being that these substances 

 are in themselves highly antiseptic. This is only partially in 

 accord with facts. Stronger alcohohc solutions of potent drug 

 constituents no doubt inhibit the more rapid multiplication 

 of most bacteria and higher fungi, but it is known that weak solu- 



