lODUM. 115 



tongue, and increase of the mucus of the mouth ; cough and 

 frothy expectoration, and a sense of heat and rawness in the 

 trachea and chest. The phenomena of irritation of the respira- 

 tory mucosa hy the out-going iodine are therefore identical 

 with those produced hy the immediate action of iodine hy 

 inhalation, hut in a minor degree. When the secretion is 

 deficient, the mucous membrane of the bronchi swollen and 

 dry, and cough useless and painful, iodide of potassium is thus 

 a valuable expectorant, quickly inducing a flow of thin mucus, 

 by establishing secretion, or by liquefying tenacious mucus 

 which may be plugging or irritating the bronchi. It is, 

 further, an indirect antispasmodic, given with great benefit in 

 asthma and emphysema. The iodide of ethyl (n on- officinal) 

 inhaled as vapour may rapidly relieve the spasm of asthma. 

 Iodide of potassium is sometimes given in other respiratory 

 diseases, e.g. in pneumonia, if the consolidation threaten to 

 persist. 



In escaping by the skin the liberated iodine produces in 

 certain individuals peculiar eruptions, generally papular or 

 slightly vesicular, rarely purpuric. The value of the drug in 

 tertiary syphilitic diseases of the skin no doubt depends partly 

 on this influence. 



6. ACTION AND USES OF THE SEVERAL PREPARATIONS CON- 

 TAINING IODINE. 



1. Cadmii lodidum : TJnguentum Cadmii lodidi. The 

 ointment only is employed, and combines the stimulant effects 

 of the two elements. It is rubbed into the skin over enlarged 

 glands, stiff joints, etc. See Cadmium. 



2. Ferri lodidum : Pilula Ferri lodidi and Syrupus Ferri 

 lodidi combine the action of the two important elements, and 

 are especially indicated and extensively employed when iodine 

 has to be administered for a length of time to anaemic sub- 

 jects. This is the form in which iodine is usually given in 

 scrofula, the syrup being a favourite remedy for strumous 

 children. 



3. Hydrarfjyri lodidum Rubrum possesses chiefly the action 

 of the per-salts of mercury, and is used accordingly. See 

 Hydrargyrum. 



4. Hydrargyri lodidum Viride is also a mercurial rather 

 than an iodide in its action, and is employed in syphilis much 

 like calomel. 



5. Sulphur is lodidum is now used externally only, and is 

 believed to produce the combined effects of the two alteratives. 



