74 ACTIVITIES OF BACTERIA. 



agents which precipitate albumin are able to precipitate, 

 from the bouillon culture of many bacteria, amorphous 

 poisons, which possess intense and, indeed, almost always 

 specific action (like the living cultures). They call these 

 poisons toxalbumins, and compare them with the " poison- 

 ous albuminous bodies" obtained from many plants (ricin 

 from Ricinus communis, abrin from Abrus precatorius, 

 etc.). Most investigators have regarded, and some still to- 

 day regard, the poisons as unstable albuminous bodies, 

 which have their origin in the bacterial cells. Often, also, 

 they are compared to snake poisons and enzymes. Like 

 these bodies, they possess a great sensitiveness to heat, 

 reagents, light, etc. 



The toxin may be obtained as a crude product by pre- 

 cipitating it with absolute alcohol or ammonium sulphate 

 from an old bouillon culture of the bacteria, which had 

 previously been freed from living organisms by a porcelain 

 filter, 1 and concentrated in vacuum. If ammonium sul- 

 phate has been used, it must first be removed from the pre- 

 cipitate obtained upon filtering by dialysis with flowing 

 water in a parchment coil, and then the toxin precipitated 

 with absolute alcohol after renewed concentration in 

 vacuum. Recently we have learned that zinc chlorid pre- 

 cipitates the bodies quantitatively, and from the precipitate 

 the toxins can be obtained by precipitation of the zinc with 

 ammonium bicarbonate and ammonium phosphate. In 

 the filtrate the toxin is precipitated with ammonium sul- 

 phate. For detailed communications upon this, see Brieger 

 and Boer (Z. H. xxi, 259, and Deut. med. Wochenschr., 

 1896, No. 49, 783). 



From the first there were strong misgivings that these 

 1 1 toxalbumins ' ' were only bodies carried down by precipi- 

 tated albumins, but having nothing to do with albumins 

 proper. 



In connection with tetanus poison it has been possible 

 for Brieger and Cohn (Z. H. xv, 1) to obtain from the 

 crude poison, under great precautionary measures, by 

 means of lead acetate and ammonia, a pure poison. This 

 presents with copper sulphate and caustic soda a faint violet 



1 Many authors have recently proved that toxins are held back in 

 part by thick porcelain filters. 



