MINERAL OR INORGANIC POISONS 41 



on to grass or fodder, which then becomes a vehicle of 

 poisoning. 



Post-Mortem Appearances. — Notable signs of arsenical 

 poisoning are — intense rose-red gastro-intestinal inflamma- 

 tion with ecchymoses and extravasations^'®; fatty degenera- 

 tion of liver, kidneys, heart, and nervous centres in pro- 

 tracted cases. Well-marked preservation of the organs 

 highly charged with arsenic is characteristic* But it is to 

 be observed that the detachability of the lining mucous 

 membranes disclosing injected submucous layers is not in- 

 variable, and depends on the concentration. Several cases 

 are on record in which inflammation was not a prominent 

 feature,^' "^ and some have been investigated where poison- 

 ing was caused by dilute weed-killer and where also in- 

 flammation was not notable. Such examples ought, how- 

 ever, to be viewed as exceptional. In some cases actual 

 perforation may be found. 



In cases of pigs poisoned by partaking of waste dip, 

 Varnell (1859) observed inflammation with effusion of 

 lymph of the membranes of the mouth and fauces, which 

 extended to the larynx and trachea, with production of 

 asphyxia. 



Treatment. — This should consist of emetics and purga- 

 tives, with milk, egg-white, and lime water as demulcents. 

 As specific antidotes, calcined magnesia and freshly pre- 

 cipitated ferric hydroxide are used. The behaviour of 

 the latter towards dissolved arsenious acid is remarkable. 

 When shaken up with a solution of arsenious acid, the 

 hydrated iron oxide fixes the arsenic, and thus withdraws 

 it from solution. This it does by the process of adsorption, 

 which is physical, and not chemical. As to whether 

 arsenic, thus rendered insoluble, is dissolved, and there- 

 fore absorbed by acid digestive juices, is uncertain, and is 

 a point worthy of experimental investigation. 



Magnesia is very efficacious in preventing gastric in- 



* In a poisoned fox examined recently the stomach, which was 

 heavily arsenical, was exceedingly well preserved, the other organs 

 being, indeed, almost entirely decomposed. 



