E UPHOBBIA CUM. 305 



a filter. Crotonoleic acid, which exists in croton seeds, was 

 fouud to be quite distinct fi'om ricin. 



The results obtained by Dr. Stillmark find further confirma- 



tion in a note in the Medical Recorder (July, p. 299), in which 

 it is stated that fifteen children, under six years of age, poisoned 

 by eating castor seeds, suffered from severe vomiting and 

 prostration, but not from catharsis. 



Ehrlich {Deutsche Med. Wochensclir.^ No, 32, p, 976, 1891) 

 reports some interesting experiments with ricin. He found 

 that injected into the veins of animals, it is fatal in doses of 

 three milligrams per kilo of body-weight ; taken internally it 

 is a hundred times less active, but still so poisonous that O'lS 

 gram is a fatal dose for an adult man. He found different 

 animals to be unequally affected by it ; guinea pigs were 

 especially susceptible to the poison, but white mice much less 

 so. The symptoms were diarrhoea and prostration: on j^os^- 

 mortem examination the appearances in some cases were such 

 as are seen in cholera, but more frequently there was a 

 haemorrhagic condition of the intestines and often of the 

 subcutaneous cellular tissue. 



Ehrlich also succeeded in rendering animals insusceptible 

 to the poison by administering gradually increasing doses 

 internally : at the end of two months of this treatment he found 

 that mice could bear a dose of 5 decigrams of ricin (sufficient 

 to kill an adult man ), the fatal dose for an unprotected mouse 

 being 35 milligrams. 



The immunity obtained was still more marked in experiments 

 on the conjunctiva; under ordinary circumstances touching the 

 membrane with a 1 per cent, solution of ricin produced intense 

 inflammation, but after several weeks of protective treatment 

 the strongest solution could be freely applied without producing 

 any effect. 



The establishment of the immunity appears to commence 

 suddenly on the sixth day, and continues to increase from that 

 time. The author insists upon the similarity between this 



IIL-.39 



