SNAKE-BITES AND POISOXOUS FISHES. 127 



C. humeralis of the W. Indies is stated by Day to have caused death in a 

 few minutes. 



The marine " cat fish " or Silurokls are as a rule too loathsome to ever 

 be much used for food. They are invariably rejected, if caught, on board 

 ship, but are, however, constantly seen for sale in the native markets. 

 Most of the species of Balistes (file fish), Tetrodon (globe fish), and Diodon 

 (porcupine fish) are rejected as being poisonous ; they are foul feeders, or 

 live on coral and other zoophites. Two cases are recorded by Sir John 

 Richardson of acute poisoning from eating portions of the liver of a 

 Tetrodon. One man ten minutes after eating it became very ill, with flushed 

 face, swollen lips, signs of intense gastro-intestinal poisoning, followed by 

 paralysis, laboured breathing, cyanosis, and death in seventeen minutes. 

 The second man died in twenty minutes. The whole fish was not more than 

 eight inches long. Many of the small kinds are constantly seen for sale in 

 the Bombay market and elsewhere, those from brackish and fresh water being 

 more wholesome than the marine varieties. Macoy states that in Australia 

 nearly all cases of fish poisoning are due to eating Arripis trutlaceous, one of the 

 sea perch. This may be sometimes due to decomposition, but fresh fish also 

 produce unpleasant results in some people, the symptoms being flushing of the 

 skin, particularly of the face, headache, vomiting, and a transient eruption, 

 generally followed by rapid recovery, but a few deaths have been noted. 



Murcma punctata, one of the "sea eels," is stated by Russell to be 

 poisonous if eaten. Mosso states that the fresh blood cf eels possesses 

 highly poisonous properties, due to the presence of ichtbyotoxin, like the 

 toxalbumens of vipers. 



Mussels or other shell-fish, though quite fresh, will sometimes produce 

 severe symptoms — nausea, vomiting, diarrhoea, syncope, numbness of the 

 limbs, and eruptions on the skin, with occasionally swelling of the tongue 

 and mucous membrane of the throat. Those taken from the open sea are 

 generally quite wholesome, the poisonous properties being derived from the 

 foul water from which they have been gathered. 



(2) Putrefaction of Fish. — This is the most common cause producing 

 poisonous symptoms. 



It is generally due to the action of micro-organisms breaking up the proteid 

 substances present into a number of chemical bodies, some of which are 

 harmless, others being very toxic. 



The proteids are first split up into albumenoses, and then finally into the 

 animal alkaloids known as " Ptomains " ; these latter were first studied in 

 detail by Selrni, and since then by Breiger, Van Ermengen, Sydney Martin, 

 and others. 



From, decomposing fish Breiger isolated the following substances : Trirae- 

 thylamine, Dimethylamine, Meihylamine, Neuridine, Cadaverine, and Putrescine ; 

 some, as cadaverine and putrescine, are but slightly toxic, others are 

 extremely so, rapidly causing death. 



