46 MATERIA MEDIC A AND THERAPEUTICS. 



the tendency to coagulation. The phosphate is believed to 

 be useful in gout, by keeping uric acid in solution. 



3. SPECIFIC ACTION AND USES. 



Although its specific action is still imperfectly known, am- 

 monia certainly appears to stimulate the central nervous system 

 generally, the respiratory centre, and the heart ; that is, to be a 

 general stimulant. It is much given in neuralgia (as the 

 chloride), and in exhausted states of the vital powers, especially 

 if respiration and circulation threaten to fail, as in typhoid 

 fever complicated with pneumonia, in the bronchitis of old or 

 weakly subjects, and in ordinary acute pneumonia with increas- 

 ing feebleness of the heart. In this way also it is useful in 

 serpent's bite, and is given internally in water, or hypodermi- 

 cally (10 to 20 minims) whilst it is applied to the wound. The 

 phosphate directly increases the amount of bile, etc. ; chloride of 

 ammonium decidedly increases the production of urea, partly, 

 at least, by its own decomposition in the liver. 



4. REMOTE LOCAL ACTION, AND USES. 



Ammonia is excreted by the kidneys and mucous mem- 

 branes, especially the respiratory tract ; not, however, as am- 

 monia, but as some other nitrogen compound. Thus, instead 

 of diminishing, it actually increases the acidity of the urine, 

 whilst the amount of urea and uric acid also rises, as well as 

 the volume of the secretion. The chloride of ammonium pos- 

 sesses these important powers most fully, the acetate less fully. 

 They are employed as diuretics in dropsies and feverish states 

 of the system. 



The bronchial secretion is distinctly increased, and ren- 

 dered more liquid and easily raised, by the carbonate and 

 chloride of ammonium. These salts prove of great service 

 as expectorants in the treatment of bronchitis when the 

 secretion is scanty and thick, or the patient feeble ; the 

 accompanying stimulation of the respiratory centre increasing 

 the coughing or expectorant power, whilst the heart is also 

 sustained. 



The mucous secretion of the stomach is affected by ammonia 

 as by the other alkalies, and the chloride is sometimes used in 

 chronic dyspepsia. Ammonia remotely stimulates the intes- 

 tines, and will cause diarrhoea if given in large doses. 



On the skin the acetate of ammonia acts as a well-marked 

 remote stimulant, and as the Liquor is one of our most common 

 diaphoretics. The chloride also possesses the same property, 

 but to a less degree. 



