INTERNAL DISEASES 405 



more on the mucous membranes of man and other animals, the 

 most important are the caustic alkalis (potash, soda, lime and 

 ammonia), and the acids (oxalic, sulphuric, nitric and hydro- 

 chloric acids). Next come the poisonous metals, zinc, antimony, 

 chromium, cobalt, copper and mercury with their salts, and the 

 metalloids, iodine, phosphorus and arsenic. Among plants 

 with an irritant action on the stomach and intestinal canal 

 may be enumerated the following, which are among the most 

 powerful of those indigenous in our soil : the autumn saffron, 

 the spurge laurel, the yew, various kinds of spurge, the labur- 

 num, the ranunculus, the larkspur, the aconite, and the poison- 

 ous fungi, etc. A sharp local inflammation, accompanied by 

 severe general symptoms, are produced by poisons found in the 

 bodies of certain kinds of melolonthae and the Spanish fly ; 

 here, too, may be classified the poison of the scorpions, the 

 millepedes and the poisonous spiders. The poison discharged 

 from the skin of the salamander, if taken internally, acts as an 

 irritant, and even may prove fatal to small animals like dogs. 

 The same thing occurs when concentrated formic acid is ejected 

 from the poisons of wasps, hornets and bees in large quantities 

 into men or animals. The poison leads not only to painful 

 local symptoms, but to marked general intoxication. 



Narcotic poisons, causing congestion of the brain, spinal 

 cord, heart and lungs, are present in the poppy, deadly-night- 

 shade, the black henbane, the honeysuckle, the thorn apple, 

 tobacco, the red foxglove, the variegated hemlock, the water 

 hemlock, cow-parsley, the darnel, the broom, the ergot, and in a 

 less degree the chick pea, the edible pea, and the leaves of the 

 potato. 



An extremely powerful poison is that obtained from St. 

 Ignatius' bean strychnine. Here, too, may be mentioned prussic 

 acid and the cyanides, alcohol and various gases, such as 

 carbon dioxide and monoxide, ordinary coal gas, ammonia 

 vapour, and sulphuretted hydrogen. All these narcotic poisons, 

 when introduced in certain quantities, produce the same symp- 

 toms in animals as they do in man. 



An equally close similarity of effect exists with regard to 

 the haemolytic snake poisons, though there are remarkable ex- 

 ceptions in the case of certain animals. Generally speaking, 



