THE QUARTERLY REVIEW OF BIOLOGY 



Slater (1893) published a report on his 

 examination of artificial carbonated waters 

 sold and prepared under factory condi- 

 tions. This was supplemented by some 

 observations on water supplies used in 

 their preparation and on experimentally 

 prepared and inoculated carbonated waters. 

 Slater used Ps. fluorescens liq., Bact. coli- 

 communis, Staph, aureus, Bact. typhosum, 

 V. cholerae and the Finkler-Prior spirillum. 

 His experiments showed that, while 

 killing or inhibition could be effected, it 

 varied with the organism in question. 

 The destructive action was intensified in 

 storage, being most noticeable after 

 three weeks, but not necessarily of a 

 constant occurrence. He observed that 

 artificial carbonated waters are by no 

 means sterile, although the numbers of 

 bacteria present are not an index of the 

 original purity of water used in the 

 preparation. 



Haenle's work (1905) supplements that 

 of Slater. He made further observations 

 on the necessity of cleanliness and sanitary 

 conditions of bottling plants. Natural 

 mineral waters are normally almost sterile 

 or completely sterile when issuing from 

 the ground. Differences were observed 

 with different kinds of bottles, i.e., 

 siphons, corked, or capped bottles. The 

 siphons were apparently the most sanitary. 

 When a sample contained more than 300 

 organisms per cubic centimeter it was 

 considered by him as having been stored 

 in dirty bottles. 



A series of articles which appeared in 

 1895 to 1899 by Czaplewsky, Draer, and 

 Morgenroth could not be obtained in 

 the original. It appears, however, from 

 available abstracts that these reports 

 were in perfect accord with those men- 

 tioned here, and in general emphasize 

 the necessity of more or less prolonged 

 storage of carbonated waters intended for 

 human consumption. 



STIMULATING ACTION ON PIGMENTATION 



Lubinski (1894) and Neumann (1897) 

 observed that pigment-producing organ- 

 isms such as Staph, aureus are devoid of 

 color under anaerobic conditions, but 

 develop abundant pigmentation when 

 reexposed to air. The cultures which 

 were grown in carbon dioxide and had 

 lost their color had the pigmentation 

 restored much more rapidly than those 

 which were subjected to hydrogen. Con- 

 sequently, the conclusion is drawn that 

 carbon dioxide exercises a certain stimu- 

 lating action on pigmentation. 



The present writer's experience has 

 shown that this observation holds 

 true also with E. prodigiosus. In an 

 atmosphere enriched with 1 per cent 

 carbon dioxide very intense pigmentation 

 bordering on a dark maroon was obtained. 

 By reducing the carbon dioxide content 

 below that which is normally found in 

 the air only a very slight color was 

 obtained, that is, a faint shade of pink. 



Hoffmann's work (1906) comprised a 

 series of experiments with carbon dioxide 

 on the colon-typhoid group in water, 

 nutrient broth and milk. High pressures 

 of carbon dioxide were used. This author 

 realized that a very small number of 

 bacteria may persist in the medium after 

 the treatment with C0 2 ; hence he used an 

 enrichment cultivation method. By add- 

 ing 1 per cent peptone broth to the 

 liquid after the carbonation, and incubat- 

 ing the whole quantity, he was able to 

 obtain subsequent growth on plates and 

 in broth, whereas he failed to detect viable 

 organisms by the usual inoculation trans- 

 fer method. Sterilization in water sus- 

 pension was obtained at 50 atmospheres 

 of carbon dioxide in from z to 3 hours 

 with Bact. coli and the dysentery bacillus. 

 Minute traces of organic matter or other 

 nutrient material when present tended to 

 render the results irregular. 



