32 BAGTEBIAL POISONS OF INFECTIOUS DISEASES. 



icids, volatile substances, and ammonium sulphate, with other salts. 

 The albumin was removed with basic lead acetate. The pepton, 

 imido-acids and salts were removed by dialysis, and finally, evapo- 

 ration in vacuo at 20-22° removed the volatile substances. The 

 toxin thus obtained is yellow, flaky, readily soluble in water, odor- 

 less, and similar in taste to gum arable. It turns polarized light 

 slightly to the left. It fails to give the Millon and xanthoproteic 

 reactions, but does give with copper sulphate and caustic potash a 

 faint, violet coloration, not identical with the rose of the biuret re- 

 Eiction. With the exception of ammonium sulphate, the metallic 

 salts, as sodium chlorid and sulphate, magnesium sulphate, potassium 

 nitrate, mercuric chlorid and potassium ferrocyanide with acetic acid, 

 fail to precipitate the purified poison. Moreover, calcium phosphate 

 which Roux and Yersin used for carrying down the diphtheria 

 poison, also magnesium carbonate and aluminum hydrate, do not 

 throw the tetanus poison out of solution. The toxin thus obtained 

 contains no phosphorus and only unweighable traces of sulphur. Of 

 the best preparation obtained by these investigators, 0.000,000,05 

 gram killed a mouse of 15 grams weight. The authors figure from 

 this that the fatal dose for a man of 70 kilograms would be 0.00023 

 gram, or 0.23 milligram, and 0.04 milligram would induce symptoms 

 of tetanus. The smallest lethal dose of atropin for an adult is 130 

 milligrams, and of strychnin from 30 to 100 milligrams. "From 

 this one can judge of the fearful weapons possessed by the bacteria in 

 their poisons." 



Fermi and Pernossi draw the following conclusions from their 

 studies of the tetanus poison : (1) Agar cultures are the most poison- 

 ous. Next come those on gelatin, and lastly those in bouillon. (2) 

 Chickens, snakes, turtles and tritons are immune to the poison. (3) 

 In the above-mentioned animals this toxin may remain and retain its 

 virulence for three days, and even longer. (4) Filtrates from agar 

 and gelatin cultures are more resistant to heat than those from 

 bouillon. Like the enzymes, the purer the tetanus poison the less 

 stability does it possess. (5) Dissolved in water, the tetanus poison 

 is rendered inert by a temperature of 55°, but in the dry state it can 

 be heated to 120° without loss of virulence. (6) When the dry 

 poison is mixed with ether or chloroform and heated to 80°, it is 

 destroyed ; but with amylic alcohol or benzol, a temperature of 100° 

 is required to accomplish this result. (7) Dissolved in water, this 

 poison is destroyed by direct sunlight after an exposure of eight to 

 ten hours (with the highest temperature on a blackened thermometer 

 at 56°) and after fifteen hours when the temperature does not exceed 

 37°. (8) In the dry state the tetanus poison can be exposed to the 

 direct sunlight for 100 hours without loss of virulence. (9) Under 

 the action of an electric current of 0.5 amp6re, continued for two 

 hours, the substance becomes inert. (10) Gastric juice destroys the 



