-----------+--------+---------------------------- | | Percentage Positive to Species | Number +-------+---------+---------- | Tested | 1 Per | 0.1 Per | 0.01 Per | | Cent | Cent | Cent -----------+--------+-------+---------+---------- Horse | 1 | 100 | 100 | 100 Dog | 91 | 83 | 35 | 0 Goat | 11 | 55 | 36 | 0 Rat | 10 | 30 | 20 | 0 Mouse | 7 | 70 | 14 | 0 Rabbit | 2 | 100 | 0 | 0 Guinea-pig | 12 | 33 | 0 | 0 Monkey | 9 | 22 | 0 | 0 -----------+--------+-------+---------+---------- The horse appears to be the most sensitive and the monkey and guinea-pig the most resistant species, while the dog would seem to have a sensitivity as near man as any of the species studied. No animal has yet been found which will give a blister from the application of mustard gas. Smith, Clowes and Marshall[22] have studied the mechanism of absorption by the skin. They find that it is quite evident that the mustard gas is at first rapidly taken up by some element on, or adjacent to, the surface of the skin and for two to three minutes it may be completely removed, and for ten to fifteen minutes partially removed by prolonged washing With an organic solvent, and to a lesser extent with soap and water. [Footnote 22: J. Pharmacol., =13=, 1 (1919).] An interesting phenomenon is observed when the untreated normal skin of one subject is impressed for five minutes upon an area of skin of another subject, which has been exposed previously to the vapors of mustard gas. Under these circumstances both donor and recipient may develop burns (due to the transposition of the poison from one skin to another), the intensity of which will vary according to the circumstances and the respective sensitiveness of the participants. The degree of transposition is most strikingly observed in the intensity of the burn on the donor’s arm. If two similar exposures are made on the arm of a sensitive man, and one of these burns is treated, so to speak, by contact for five minutes, with the skin of a resistant man, the treated burn will be markedly less severe than the control, in some cases being entirely prevented. If, however, the recipient is equally sensitive to or more sensitive than the donor, the burns on the latter will exhibit far less difference. Both treatments may be effected at once, using two recipients, one more, and the other less, resistant than the donor. In such a case the burn brought into contact with the more resistant skin will be the less severe.