490 



SCIENCE. 



[X. S. Vol. XXI. Xo. 5-35. 



III. Many bacteria may be grown readily 

 upon synthetic culture media. 



IV. From those readily growing on such 

 media I have chosen for study B. pyocy- 

 aneus, B. prodigiosus, B. ruber halticus, 

 B. rosaccus, B. met alio ides, B. violaceus, 

 B. janthinus. 



V. These bacteria may be grown with or 

 without pigment formation. 



VI. Whether producing pigment or not, 

 these ehromogenic bacteria give the same 

 metabolic products, as far as these have 

 been analyzed, e. g., acids, ammonia, alco- 

 hol, benzol derivatives and albuminous 

 bodies. 



VII. The metabolic products are as fol- 

 lows : B. prodigiosus, aldehydes, formic, 

 acetic and citric acids; albumin. B. rosa- 

 ceus, B. metalloides, formic and acetic 

 acids; albumin. B. ruber balticus, formic 

 acid; albumin. B. violaceus, aldehydes, 

 formic acid; albumin. B. janthinus, for- 

 mic acid; albumin. B. pyocyaneus, alde- 

 hydes, formic acid, mere^iptan, 11,8 ; al- 

 bumin. 



The Intracelhdar Toxins: V. C. Vaughan, 



University of Michigan. 



Bacterial cellular substance is obtained 

 in large amount by growth on the large 

 tanks which have been used for some years 

 in the author's laboratory. After fourteen 

 days of growth, the cell substance is re- 

 moved, washed with water and absolute 

 alcohol, then thoroughly extracted with 

 ether, dried, pulverized, weighed and heat- 

 ed in a reflux condenser with sodium aleo- 

 holate. This splits the cell substance into 

 a toxic and a non-toxic portion. The toxic 

 part is soluble in absolute aicohol, while the 

 non-toxic is insoluble in this reagent. The 

 alcoholic solution is neiitralized with hydro- 

 chloric acid and the sodium chloride, which 

 forms, is removed by filtration. The fil- 

 trate is precipitated with an alcoholic solu- 

 tion of platinum chloride which prer-ipi- 



tates the toxin. The platinum precipitate 

 is suspended in absolute alcohol and de- 

 composed with hydrogen sulphide, after 

 which the alcoholic solution of the toxin is 

 evaporated in vacuo. Animals have been 

 immunized with this toxin both to the liv- 

 ing germ and to the toxin itself. Animals 

 treated with non-fatal and gradually in- 

 creased doses of the toxin acquire immu- 

 nity and furnish a blood serum which is 

 both antitoxic and bacteriolytic. The 

 toxin gives all the proteid color reactions. 

 It is apparently an acid and combines with 

 organic bases. 



The non-toxic portion of the germ sub- 

 stance, or that which is insoluble in alcohol, 

 is soluble in water, and with aqueous solu- 

 tions of this substance bacteriolytic im- 

 munity is easily induced. Toxins have 

 been obtained from colon, typhoid, and an- 

 thrax bacilli and animals have been im- 

 munized to the first two. 



(To be published in the Journal of the 

 American Medical Association.) 



Relation of the Index of Alkalinity to the 

 Production of Diphtheria Toxin: A. P. 

 Kitchens, Glenolden, Pa. 

 A study of the reaction of bouillon be- 

 fore and after sterilization shows that in 

 media containing carbohydrate the rise in 

 acidity after sterilization varies according 

 to the temperature of the sterilizer. This 

 is most important in the production of 

 diphtheria toxin. Bouillon prepared ac- 

 cording to the method of Smith, and steril- 

 ized in the autoclave, showed after steril- 

 ization varying indices of alkalinity. The 

 reaction after sterilization of sugar-free 

 bouillon is very uniform. And as the re- 

 action of bouillon for the production of 

 diphtheria toxin mu.st be very exact, it is 

 advantageous to add the dextrose after 

 sterilization. The meat jiiice is neutralized 

 to litmus, planted with the colon bacillus 

 and incubated over night to destroy the 

 muscle sugar. The bouillon is made from 



