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The oil which gives all species of the onion family their charac- 

 teristic odor, consists of oxide and sulfides of allyl. According to the 

 National Dispensatory, rectified oil contains mainly a sulfide compound 

 (C3H:;)2S. This compound is said to possess a stimulating effect upon 

 the organs of the digestive system. If taken in excessive quantities it 

 produces nausea, vomiting, colic and diarrhoea. When in contact with 

 the skin it reddens it and may even vesicate it. In mucous membranes 

 this effect would no doubt be even more pronounced. 



In summarizing the evidence pointing to wild onion as the probable 

 cause of poisoning the cows in question, the following facts stand out 

 prominently : 



1. Apparently healthy cows were taken from a pasture where feed 

 was scant and turned into a woods pasture where they found and grazed 

 heavily on a patch of succulent wild onions. 



2. Symptoms of poisoning appeared within twelve hours after pas- 

 ture was changed. 



3. The attending veterinary found no other cause, aside from 

 forage poisoning, which might have been responsible for the condition 

 of the affected cows. 



4. The characteristic odor of wild onion was strongly pronounced 

 in the milk and the whole system of the poisoned animals. 



5. No other plant was found in the pasture, aside from wild onion, 

 to which the poisoning could be attributed. 



6. The poisoned cows refused to eat any ordinary feed, but when 

 one of them was offered a bunch of wild onions she manifested a greedy 

 appetite for them. 



7. The oil which gives the species of Allium their characteristic 

 odor is known to have an irritating effect on skin and membraneous 

 tissues, and causes digestive disturbances if taken in excess. The bulblets 

 of wild onion undoubtedly contain this oil in comparatively large quan- 

 tities. 



8. A number of plants closely allied to wild onion are definitely 

 known to be poisonous, and some of the symptoms of poisoning pro- 

 duced by them, such as gastro-enteritis, coma, and paralysis, are quite 

 similar to those shown by the cows in question. 



