106 GERLACH ON THE ITCH AND MANGE. 



hominis, only the female is longer and not so broad as 

 that of the latter. The eruption ensuing on the skin in 

 which the sarcoptes equi has spread is very similar to the 

 appearance of itch in man, only not so distinctly recognised. 

 We cannot be certain of the real nature of the disease until 

 the insect is found, and the ordinary methods of searching 

 for acari fail to effect this, as proved by the parasite having 

 eluded detection until so recently. Gerlach's plan to obtain 

 the sarcoptes equi is to place a crust or scab on the skin of 

 the arm, and bind it there. There is nothing to be appre- 

 hended from this, and in the course of twelve hours the para- 

 sites are observed on red spots as white points, readily 

 caught on a needle, to be submitted to a careful examina- 

 tion. A little turpentine oil rubbed around the part where 

 the scab has been placed suffices to destroy any remaining 

 insects, and to ensure immunity from further consequences. 



There have been numerous cases recorded of transmission 

 of this disease from horse to man.* Observations and ex- 

 periments prove : 



Istty, That sarcoptes equi may live in man, developing the 



* To the many instances of communication of this form of horse 

 mange to the human being, Gerlach has added the following list of 

 references : 



1. Viborg Sammlungen, &c,., vol. i. p. 281. 



2. Osiander Abhandlung uber Kuhpocken, 1801, p. 3. 



3. Sik Unterricht fiir den Landwirth, 1807, p. 56. 



4. Grognier Jahresbericht uber die Lyoner Schule in Annul, de Tagi4- 

 culture franc, 1817. 



5. Greve Erfahrungen, vol. i. 1818, p. 77. 



6. Froriep's Notizen, vol. v. 1823, p. 45. 



7. Magazin von GTJRLT und HERTWIG, vol. i. pp. 187-190, and vol. 

 xix. pp. 281- 283. 



8. Mittheilungen aus den Veterindr-Berichten von GERLACH und 

 LEISERING, 1st year, pp. 6, 7, 8; 2nd year, pp. 14, 15, 18; 3rd year, 

 pp. 14, 17. 



