COMMON MEDICINES 285 



water. For antiseptic and disinfecting purposes, it may be 

 used four to seven grains to the pint. 



Iodin. — Iodin occurs as bluish black, heavy crystals, readily 

 soluble in alcohol and ether, and but slightly soluble in water, 

 although it dissolves in water readily if potassium iodid is added. 

 Tincture of iodin is a solution of iodin and iodid of potash in 

 alcohol and contains about 7 per cent iodin. Lugol's solution 

 is composed of iodin, 5 ; iodid of potash, 10 ; water, 100, — giving 

 5 per cent iodin. 



Iodin is one of our most useful and dependable disinfectants 

 and germicides for surgical work, wound treatment, etc. It is 

 especially valuable in skin disinfection as for castration, or in 

 treatment of the navel cords of the new born. For skin dis- 

 infection, navel cords, etc., the tincture is used in full strength. 



Lugol's solution is useful and reliable for disinfectant pur- 

 poses, diluted in water at from 2 to 4 per cent. For some pur- 

 poses it is used still more dilute as in abortion and sterility 

 work. When iodin is used externally by repeated treatment as 

 a liniment for sprains, bursal enlargements, arthritis, etc., its 

 slow, mild, but persistent, irritating and stimulating action is 

 very useful. It is also very effective as a fungicide as in ring- 

 worm. 



Iodin is used internally for actinomycosis (see Lecture 

 XXXII), where it is given internally in the form of iodid of 

 potash or it may be injected as the tincture or as Lugol's solu- 

 tion by hypodermic, directly into the diseased mass. 



Iodin in the form of iodid of potash is useful also, when given 

 to pregnant dams to prevent goiter in young pigs, and lambs, 

 and to prevent hairless pigs, etc. 



When used internally in excess, the warning symptoms are : 

 catarrhal conditions at eyes and nose, scurvy skin, digestive dis- 

 turbances, and refusal of food. 



Iodoform. — This is used for external and local application. 

 It prevents infection of wounds and acts as a local antiseptic. 

 Iodoform is useful as a dressing for wounds, especially after 

 they have commenced to heal. It may be used alone or mixed 

 with twice its bulk of powdered boracic acid and dusted over 

 the wound surface. 



Common lime. — Common lime is an irritant, it neutralizes 

 acids and is astringent. Saturated solution, which is very 

 dilute, is useful in diarrheas and indigestions of young animals, 



