ABSORPTION B Y THE SKIN IN MAN. 687 



method, could observe no absorption of absolute alcohol by his own skin 

 in an hour and a half, and Bitter 1 denies entirely the absorption of 

 alcohol or alcoholic solutions of salts by the human skin. Winternitz 2 

 got spectroscopic evidence of lithium in the urine after keeping the 

 skin of the arm in contact with an ethereal solution (with a little added 

 alcohol) for three and a half hours, but missed the effect with a purely 

 alcoholic solution. The last-mentioned observer also denies the state- 

 ment of Parisot, 3 that solutions of atropine in alcohol and chloroform, 

 applied to the forehead, cause mydriasis. 



It would appear that previous removal of the grease of the skin 

 by ether allows a slight absorption of watery solutions to take place, 

 for Winternitz 4 got traces of lithium in the urine on applying a watery 

 solution of the chloride to the skin cleaned with ether, but not till nine 

 hours after the application. 



If a substance applied to the skin is volatile at the temperature 

 of the body, the vapour may possibly pass into the capillary spaces 

 between the epidermic cells, and dissolve in the fluid in the sweat 

 ducts, and so finally reach the blood vessels, and be absorbed ; but in 

 experiments with such substances the greatest precautions must be 

 taken to exclude absorption by the respiratory tract, and again with 

 human skin the results of different observers are conflicting. Eohrig's 5 

 positive results with tincture of iodine are denied by Fleischer, 6 who, 

 wearing a mask with a tube to the outer air, found no iodine in the 

 urine up till six hours after an application to the skin of the back for 

 one and a half hours. Next morning Fleischer found iodine in the 

 urine, but this may have been absorbed by the lungs during sleep, 

 or the result of the destructive action of the substance on the 

 epidermis. Mesnil, 7 placing the arm in a Mosso's plethysmograph, filled 

 with vapour of iodine, could get no evidence of absorption after thirty- 

 two hours' exposure. On the other hand, guaiacol is asserted by several 

 observers to be absorbed. 8 



Oily solutions and unguents, since they " wet " the skin, one would 

 expect to be capable of absorption, but such substances are viscous and 

 must be mechanically forced into the intercellular spaces and hair 

 follicles, if any marked effect is to be obtained. According to Winter- 

 nitz, 9 the mere application of oily solutions of veratrine and aconitine to 

 the skin of man is without effect. Baschkis and Obermayer 10 obtained 

 evidence of presence of lithium in the urine three hours after rubbing 

 in an ointment of lithium carbonate, oleic acid, and lanoline, but 

 Fleischer n could not obtain evidence of absorption of unguents holding 

 potassium iodide, veratrine, morphia, quinine, and salicylate of soda, nor 

 could Fubini and Pierini 12 find salicylic acid in urine after painting a 

 solution in oil of almonds on the hand and forearm. 



But the most important case is that of mercurial ointment, which is 

 undoubtedly absorbed into the system. In this, in addition to fine 



1 Diss., Erlangen, 1883. 2 Loc. cit. 



3 Compt. rend. Acad. d. sc., Paris, 1863, tome Ivii. p. 327. 4 Loc. cit. 



5 Loc. cit. 6 Loc. cit. 



7 Oentralbl.f. PhysloL, Leipzig u. Wien, 1894, Bd. vii. S. 775. ref. 



8 Sciolla, "Cronaca della clinica medica di Geneva," 1892-93, p. 191 ; Linossier and 

 Launois, Compt. rend. Soc. de. biol., Paris, 1894, pp. 108-110 and pp. 214-215; Gurnard 

 and Stourbe, ibid., 1894, pp. 180-182. 



9 Loc. cit. 10 Centralbl. f. klin. Mcd., Bonn, Bd. xii. S. 65. 

 11 Loc. cit. 12 Loc. cit. 



