232 BULLETIN OF THE BUREAU OF FISHERIES. 



receptacles. The infected portions of potato were fed to rabbits and guinea pigs in 

 doses of three cubes to each individual. The animals were then isolated and allowed 

 nothing more to eat. All the rabbits, eight in number, died within 12 hours. Of these, 

 two died in two hours after having suffered from severe diarrhea. Of the guinea pigs, 

 four in number, two survived and two died. 



An autopsy demonstrated the same conditions which have been described for 

 persons who have succumbed to the effects of mussel poisoning, and microscopic exami- 

 nation of the cardiac blood and of the intestinal contents revealed the presence of 

 the bacillus in question. 



After these results of natural infection he injected from 15 to 20 drops of 24-hour 

 cultures into the skin of rats and rabbits, but both cutaneous and subcutaneous injec- 

 tions proved to be without effect. However, if injected into the peritoneum in small 

 quantities it produced death in rabbits and guinea pigs in from 8 to 24 hours. The 

 clinical and pathological phenomena presented by these animals were the same as of 

 those naturally infected. An injection of these bacteria into the blood vessels of the 

 ears of four rabbits produced no harmful results. Cultures from the alimentary tracts 

 of animals which died as a result of these infections if taken within 24 hours after death 

 are just as capable of infecting other animals when ingested as are the original cultures 

 from the mussel liver. As the cultures grow older they become less virulent in their 

 effects and after a few hours cause nothing more serious than diarrhea when injected 

 into the peritoneum. 



Lustig admits that the above evidence is not complete enough to definitely prove 

 this organism to be the cause of the poison which is sometimes found in the mussel 

 liver. It is very suggestive, however, and calls for further research when the opportunity 

 presents itself again. Other investigators, Netter et Ribadeau-Dumas (1907), who 

 secured some of these poisonous mussels at Calais, France, were unable to isolate a 

 specific germ. 



CHEMISTRY OF MUSSEL POISON. 



The chemical nature of the poison classes it with the ptomaines according to 

 Schmidtmann (1888), while Virchow (1885) is inclined to group it with the alkaloids. 

 Our first knowledge of its chemical properties was furnished by Salkowski (1885), who 

 extracted the poison by means of alcohol. He found that alcoholic solutions of non- 

 poisonous mussels were almost colorless, while those from the diseased livers of poisonous 

 mussels were golden yellow in color and if treated with warm concentrated nitric acid 

 gave a grass-green color. He furthermore found that the activity of the poison is not 

 affected by heat up to no C. but that it is destroyed by warm sodium carbonate. 



Mytilotoxin is a poisonous compound which Brieger (1886, 1888, 1889) succeeded 

 in isolating from the livers of toxic mussels. Its formula according to his determina- 

 tions is C e H 15 N0 2 . This compound, Brieger claims, is the specific curare-like active 

 toxin of the sea mussel. 



The method of extracting the mytilotoxin is as follows: Several hundred of the 

 pathologic mussels are heated in water with some hydrochloric acid, and the mixture 

 is then filtered. The poisonous compound is in the filtrate as hydrochloric mytilotoxin. 

 This filtrate is evaporated to dryness, and the residue is dissolved in alchool. The alco- 

 holic solution is neutralized with sodium carbonate, then acidified with nitric acid, and 



