ABSORPTION THROUGH THE SKIN. 539 



gory belong the rare cases of blood-sweating, hematidrosis , which may also be uni- 

 lateral, and in which, at times, the bloody discharge from the pores of the skin 

 appears to take place vicariously for absent menstruation. More commonly, how- 

 ever, the condition has been one of the symptoms of a profound nervous disorder, 

 especially convulsive seizures. Blood-corpuscles, rarely blood-crystals, have been 

 found in the escaping drops of red sweat. Yellow fever also is, at times, attended 

 with bloody sweats. Biliary pigment has been found in the sweat of jaundiced 

 persons; a bluish-black discoloration, further a blue color from indigo, from pyo- 

 cyanin (the rare blue pigment of pus), produced by the bacillus pyocyaneus, or 

 from ferric phosphate, are among the rarest exceptions. Such colored sweating 

 is designated chrornidrosis. 



Between the epidermal scales and upon the hair there live numerous micro- 

 organisms, which, however, must be designated as innocuous: Two varieties of 

 saccharomyces ; the leptothrix epidermidis and various bacteria on surfaces the 

 seat of intertrigo, namely, five varieties of micrococci; and between the toes, the 

 bacterium graveolens and bacillus saprogenes, which generate the odor of the sweat 

 of the foot. Yellow, blue, and red sweat are likewise caused by bacteria, the last 

 by the micrococcus haematodes. Red sweat and black sweat may be caused also 

 by a variety of torula. Within the lesions of acne and in comedones, there vegetates 

 a thick bacillus, which Hodara considers as the cause for the formation of the 

 pustule. 



Grape-sugar has been found in the sweat in cases of diabetes; rarely uric 

 acid, in individuals with calculi; cystin, in cases of cystinuria. In the fetid sweat 

 of the feet, leucin, tyrosin, valerianic acid, and ammonia are present. This con- 

 dition can be corrected only by the most systematic and scrupulous cleanliness. 

 To the foot-baths, anti-fermentative and bactericidal substances should be added, 

 such as salicylic acid or potassium permanganate. Odorous secretion of sweat is 

 designated as osmidrosis, fetid sweating as bromidrosis. In the sweating stage of 

 intermittent fever, considerable calcium butyrate has been found; in cases of 

 puerperal fever, lactic acid. The viscid sweat of acute articular rheumatism is 

 said to contain a greater amount of albumin, as does also the sweat attending 

 enforced diaphoresis. 



With respect to abnormalities in the secretion of the cutaneous sebum, there 

 should be mentioned the pathological increase in secretion seborrhea which 

 occurs either locally or disseminated over the entire skin. In cases of premature 

 baldness, there is increased production of sebum on the scalp. Diminished secre- 

 tion of sebum asteatosis of the skin causes the skin to become brittle and rough, 

 in part locally and in part extensively. Often, as upon the bald head in the 

 aged, the sebaceous glands undergo atrophy. If the excretory ducts of the seba- 

 ceous glands become obstructed, the sebum accumulates, in greater or lesser 

 amount. Not rarely, the excretory ducts are occluded by particles of dirt, gran- 

 ules of ultramarine derived from washing blue, and vegetable fibers from the 

 clothing. By pressure, the fatty, worm-like comedo is discharged. 



ABSORPTION THROUGH THE SKIN. GALVANIC CONDUC- 

 TIVITY. 



After prolonged exposure to water, the epidermis becomes moist and 

 swollen.. On the other hand, the skin is incapable of absorbing sub- 

 stances, either salts or vegetable poisons, from watery solutions, such as 

 baths. This inability is due to the fat normally present in the epi- 

 dermis and the pores of the skin. If, therefore, substances dissolved 

 in such fluids as dissolve and extract the cutaneous sebum, as al- 

 cohol, ether, and particularly chloroform, are applied to the skin, 

 they may be absorbed in small amounts in larger measure in rabbits. 

 Volatile substances, such as carbolic acid, that exert a corrosive effect 

 upon the epidermis, are capable of absorption through the injured areas. 

 Absorption does not take place from ointments applied simply to the 

 skin. In the case of persistent vigorous inunction, there occurs, at times, 

 a forcible introduction into the pores of the skin, not rarely in association 

 with mechanical lesions in the continuity of the layers of epidermis. 



