ii2 MATERIA MEDIC A AND THERAPEUTICS. 



chemical combination with the albuminous constituents of the 

 parts. At the same time it stains the epidermis of a deep brown, 

 causes considerable pain ; and is absorbed into the blood, partly 

 by the skin and partly by the air of respiration in the form of 

 vapour. It is also a powerful antiseptic and disinfectant. 



The tincture, liniment, and ointment of iodine are exten- 

 sively used as stimulants and disinfectants to foul, callous ulcers, 

 much like nitrate of silver ; as vegetable parasiticides in ring- 

 worm ; and as counter-irritants in subacute or chronic inflam- 

 mation of joints, periosteum, lymphatic glands, the pleura, and 

 the lungs. In these instances the chief effect is doubtless 

 stimulation, but a certain amount of the iodine is absorbed, and 

 acts specifically, as will be presently described. Iodine in 

 solution is injected into cysts, goitres, hydrocele, etc., with 

 much success. 



Iodide of potassium applied to the unbroken skin is neither 

 irritant nor capable of being absorbed, unless decomposed by 

 the sweat. It is readily taken up from the exposed mucous 

 membranes. How much specific value can be attached to the 

 iodide liniment is doubtful. 



Internally, the local action of free iodine is also irritant, 

 and it is successfully applied to the gums in periosteal tooth- 

 ache. Inhaled into the respiratory passages, it gives rise to 

 cough, sneezing, severe pain over the frontal sinuses, distress- 

 ing pains in the chest, and dyspnoea. Combinations of iodine 

 with creasote and various soothing volatile substances, such 

 as chloroform and ether, have lately come into repute as 

 continuous inhalations in the so-called " antiseptic " treatment 

 of phthisis, bronchitis, and other forms of chronic lung disease. 



In the stomach and bowels, although it is gradually con- 

 verted into the iodide or iodate of sodium, the irritant effects of 

 free iodine are continued, with abdominal pain, sickness, and 

 diarrhoea as the result. The iodides of potassium and sodium 

 have rarely this effect, and it is only in the form of a salt that 

 iodine is now administered internally. Iodide of potassium is 

 also decomposed in the stomach, the sodium salt and albu- 

 minate being formed from it. 



2. ACTION ON THE BLOOD. 



Iodine is freely absorbed into the blood from mucous siir- 

 faces, and the sodium iodide quickly enters from the alimentary 

 canal. In the blood the element is at first combined with 

 sodium; but this salt appears to be decomposed, the iodine 

 for a time set free, some of the red corpuscles broken down (if 

 the amount of iodine be large), and bloody effusions and bloody 

 urine make their appearance. Such results are to be carefully 



