FISH AND ARROW POISONS 55 



stops; but it may continue to beat for several minutes after the respiration has ceased. But 

 all these progressive symptoms are without convulsion. Among warm-blooded animals, on 

 the contrary, convulsions are constant, and the sequence of the symptoms dyspnoea, slowing 

 of the pulse, giddiness, falling down, then convulsions with expulsion of the urine and faeces. 

 When the dose is short of a fatal one, the symptoms are as follows: Evident giddiness 

 and distress; the tongue is protruded, the breath is taken in short, hurried gasps, there is 

 salivation, and convulsions rapidly set in, preceded, it may be, by a cry. The convulsions 

 pass into paralysis and insensibility. After remaining in ths state some time, the animal 

 again wakes up, as it were, very often howls, and is again convulsed; finally, it sinks into a 

 deep sleep, and wakes up well. 



Dr. K- Winslow in his work on Veterinary Materia Medica and Thera- 

 peutics, gives the Toxicology of Hydrocyanic Acid as follows : "Three stages may 

 be distinguished in fatal poisoning. First : a very short period elapses before the 

 symptoms appear. There are giddiness, difficult breathing, and slow pulse in this 

 stage. Second : the pupils dilate, vomiting may occur, and the animal utters loud 

 cries. Spasmodic defacation, micturition and erections may be present, with con- 

 vulsions and unconsciousness. Third : the last stage is characterized by col- 

 lapse, spasms, general paralysis and death. The subacute form of poisoning 

 may ensue and prove fatal, or, owing to the volatile character of the drug,, 

 complete recovery may take place within one-half or three-quarters of an hour. 

 Occasionally dogs continue to be paralyzed for several days and get well. 

 The minimum fatal dose recorded in man is 9/10 of a grain of pure acid, or 

 about 50 drops of the medicinal solution. Four to five drachms of the diluted 

 acid frequently, but not invariably, causes subacute poisoning and death, in 

 horses, within an hour. One or two drachms of the pharmacopoeial prepara- 

 tion usually kills dogs within ten minutes." 



Poisoning from Toxalbumins, Black Locust, Ricinus and Abrus. 



In recent years much work has been done with a class of poisons, known as 

 toxalbumins. These are of especial interest because many of the bacteria pro- 

 duce such poisons. Some of the fungi responsible for "forage poisoning" pro- 

 duce, it is thought, toxalbumins. In recent years a number of cases of horse 

 poisoning from Black Locust bark have been reported. The poisoning from 

 castor oil bean (Ricinus') and from Abrus are also of this class. 



Castor Oil Seed and Abrus. One of the best known of the toxalbumins 

 is that occurring in the castor oil seed, known as ricin. This albuminous sub- 

 stance is very poisonous, more so than strychnin and prussic acid. Ricin 

 coagulates the blood. Blyth in his work on poisons states : 



If castor-oil seeds are eaten, a portion of the poison is destroyed by the digestive processes; 

 a part is not thus destroyed, but is absorbed, and produces in the blood-vessels its coagulating 

 property. Where this takes place, ulcers naturally form, because isolated small areas are de- 

 prived of their blood supply. These areas thus becoming dead, may be digested by the gastric or 

 intestinal fluids, and thus, weeks after, death may be produced. The symptoms noted are nausea, 

 vomiting, colic, diarrhoea, tenesmus, thirst, hot skin, frequent pulse, sweats, headache, jaundice, 

 and death in convulsions or from exhaustion. Animals may be made immune by feeding them 

 carefully with small doses, gradually increased. 



The post-mortem appearances are ulceration in the stomach and intestines. In animals the 

 appearances of haemorrhagic gastro-enteritis with diffuse nephritis, haemorrhages in the mesen- 

 tery, and so forth have been found. 



A toxalbumin also occurs in the Jequirity seed (Abrus precatorius) which 

 causes similar effects and symptoms. That the poisons are not the same have 

 been shown by experiments with animals. It is known that animals may become 

 immune by repeated doses of Jequirity against abrin and the principle of castor 

 oil does not produce immunity against abrin, nor does abrin confer immunity 

 against the ricin of the castor oil bean. The abrin when applied to the con- 



