IODOFORM 235 



the lower animals, potassium iodide is regarded as more 

 valuable in chronic rheumatism. The action of iodine in 

 benefiting local disorders, when applied externally, is due 

 to its counter irritant effect, rather than to absorption. 



Administration. — Potassium iodide is given in solution. 

 Sodium iodide and syrup of hydriodic acid are simply sub- 

 stitutes for potassium iodide. 



loDOFORMUM. Iodoform. C H I3. (U. S. & B. P.) 



Derivation, — Alcohol, potassium carbonate, iodine, and 

 water are heated together. C,HeO + 2 KHCO3 + 81 = 2 

 CHI3 + 2 KI + 2 CO, + 3 H,0. 



Iodoform contains over 90 per cent, of iodine. 



Properties. — Small, lemon-yellow, lustreless crystals of 

 the hexagonal system ; having a peculiar and very penetrat- 

 ing persistent odor, somewhat resembling that of saffron 

 and iodine, and an unpleasant and slightly sweetish and 

 iodine-like taste. Very slightly soluble in water ; soluble in 

 52 parts of alcohol, and in 5.2 parts of ether. Very soluble 

 in chloroform, benzine, fixed and volatile oils. 



PREPARATION. 



Unguentum lodoformi. Ointment of Iodoform (1-10). 

 (U. S. &B. P.) 



Action External. — Iodoform is an antiseptic, local anaes- 

 thetic, stimulant, protective, and dessicant agent. While 

 many forms of bacteria will grow in iodoform, it is never- 

 theless a very valuable antiseptic. The antiseptic properties 

 seem to be brought out by its decomposition when iodine is 

 set free, and this decomposition goes on more readily iu the 

 presence of bacterial growth — in animal tissues and fluids — 

 attended by the formation of toxins. Iodoform is particu- 

 larly useful in septic and suppurating wounds. When 

 applied over extensive surfaces absorption and poisoning 

 may occur. The symptoms of iodoform poisoning are most 

 diverse. The writer has had the fortune, or misfortune, 



