GENERAL ABSORPTION. 615 



Absorption by the skin also takes place, especially when a substance 

 is kept in prolonged contact with it, as in the case of painters who do 

 not cleanse their hands from white lead, and are attacked with the 

 dropped wrist or paralysis of the extensor muscles of the forearm. 

 In the thin- and moist-skinned Amphibia, absorption by the integument 

 is very active ; for if kept in a condition of drought, these animals be- 

 come extremely attenuated; whilst they rapidly swell out, if then placed 

 in a moist atmosphere, or upon damp earth, thus proving that their 

 skin is both absorbent and exhalant. A dog placed in an air-tight 

 vessel, with its head uninclosed, has been killed by the vapor of the 

 oil of bitter almonds absorbed only through the skin. In regard to 

 Man, absorption through the skin, if this be whole, is not very active; 

 indeed, it has been, though erroneously, denied. The non-vascular 

 cuticle impedes this process, and, in this way, is of great importance, 

 especially in the practice of certain arts, in which the body is subject 

 to contact with deleterious agents. Nevertheless, water may be ab- 

 sorbed by the whole skin, for the weight of the body is increased after 

 the use of warm baths. (Madden.) Shipwrecked sailors, destitute of 

 fresh water, find that, by immersion in the sea, or by wetting the clothes 

 in sea-water, thirst is relieved ; this may be partly attributable to a 

 diminution of the exhalation of water from the blood through the skin, 

 owing to the prevention of evaporation, but it is doubtless partly also 

 due to direct absorption. In the use of very hot baths, above the tem- 

 perature of the blood, more water is lost, by perspiration and pulmo- 

 nary exhalation, than is absorbed, so that the body is lighter after such 

 a bath; in a bath of 90, the processes of absorption and exhalation 

 are balanced, no change taking place in the body-weight ; in tepid and 

 cold baths, cutaneous absorption exceeds exhalation, and the body gains 

 in weight. Saline substances, such as iodide of potassium, cyanide of 

 potassium, nitrate of potash, or chloride of ammonium, dissolved in 

 baths, do not, according to some, enter the system ; but others allege 

 that they may be found in the blood and urine. The use of medicinal 

 baths is based on the supposition that they are so absorbed ; and the 

 discrepancies between the results of different experiments, may, in part, 

 depend on the employment of baths at different temperatures, which, 

 as just stated, produce different results. A condition of exhaustion 

 favors cutaneous absorption. The softening of the cuticle greatly 

 facilitates the process : thus, an onion crushed and worn in the shoe, 

 will cause the breath to smell ; garlic poultices applied to the arm, and 

 lint dipped in turpentine, to the body, produce characteristic odors in 

 the urine ; jalap poultices may have an aperient effect ; whilst appli- 

 cations of belladonna to the skin have been followed by dryness of the 

 throat, dimness of sight, and by alarming, sometimes fatal, symptoms 

 of poisoning. The introduction of foreign substances through the 

 skin is greatly aided by the thinness of the cuticle and by friction, as 

 is illustrated by the effects on the system of mercurial inunction, and 

 also by the rubbing in and consequent absorption of cod-liver oil ; but 

 both these substances are absorbable even without friction. 



The importance of the non-vascular cuticle as a protective covering, 

 antagonistic to absorption, is shown indirectly by the effects of its re- 



