MICROSCOPIC DRAWING AND ENGRAVING. 
/ 
63. That the itch is occasioned by such an insect is by no 
means a modern doctrine. Kirby mentions a Moorish physician, 
who, in the twelfth century, affirmed that the malady was pro¬ 
duced by little mites or lice that creep under the skin of the 
hands, legs, and feet, producing pustules full of matter; he 
quotes also te Joubert,” another ancient physician, who describes 
Fig. 42.—VIEW OF THE ITCH INSECT, DRAWN WITH A CAISFRA 
BY DR. MANDL, MAGNIFIED 120 TIMES IN ITS LINEAR, AND 
THEREFORE 14400 TIMES IN ITS SUPERFICIAL DIMENSIONS. 
the itch insects under the name of u sirones,” and says they are 
always concealed beneath the epidermis, under which they creep 
like moles, gnawing it, and producing a most troublesome itching. 
It was supposed by some that they were identical with lice; but 
Dr. Adams showed that this could not be the case, since they live 
under the cuticle; he speaks of them as living in burrows which 
they have excavated in the skin, near a lake of water, from which 
if they be extracted with a needle, and put upon the nail, they 
show in the sun their red heads and the feet with which they 
walk ; they have been extracted and delineated with the aid of 
the microscope by many modern observers. The individual 
delineated in fig. 42, was drawn by my friend Dr. Mandl, well 
known for his great work on microscopic anatomy. 
96 
