78 YETEEINAEY TOXICOLOGY 



As a point of medico-legal significance, it must be 

 remembered that ammonia is developed in putrefaction. 

 Judgment will therefore need to be exercised in express- 

 ing an opinion. 



STRONG ACIDS AND ALKALIS. 



Effects. — The effects of concentrated alkalis (caustic soda 

 and caustic potash) and acids (sulphuric, nitric, and hydro- 

 chloric) are due to the profound chemical action which 

 they exercise upon the living tissue, leading to its destruc- 

 tion, to intense corrosion, and local lesion, followed by 

 vomition, colic, purgation, exhaustion, and death by shock. 



All these agents attract water, and thus act as powerful 

 dehydrants, a property which is, however, particularly 

 characteristic of strong sulphuric acid. The alkalis, 

 further, decompose fats and proteins ; whilst the acids — in 

 particular nitric acid — coagulate the latter. 



Corrosion of the mucous membranes of the mouth, 

 tongue, and pharynx will be observed. 



When strong sulphuric acid is swallowed it causes retch- 

 ing, and, if possible, vomition of bloodstained matter, with 

 shreds of mucus. The local irritation and swelling of the 

 lips, tongue, fauces, and throat, are very marked, and cause 

 suffocation. 



Characteristic of nitric acid is the intense yellow colora- 

 tion of the epithelium, which has been known in man to 

 extend through the whole of the alimentary tract. 



Dilute sulphuric or other acid is often given to horses to 

 improve condition. This it fails to do, and an overdose 

 causes acute poisoning. If this treatment is persisted in, 

 chronic disturbance of the digestion, with serious loss of 

 condition and general health, results. 



Concentrated alkali (caustic potash or caustic soda) 

 destroys the membranes, and sometimes causes perforation. 

 According to Hertwig, 2 drachms of caustic potash in 

 6 ounces of water killed a horse in thirty-six hours, and 



