ACAEUS SCABIEI. 33 



forming hard knots. The entire right arm, especially^the fore- 

 arm and hand, appeared enlarged and thickened about one half, as 

 in elephantiasis, unyielding, covered with knot-like elevations, and 

 on the back of the arm with bran-like scales. Immobility and 

 thickening of all the fingers, want of strength, weight, insensi- 

 bility, and uselessness of the right arm, with violent pain in it, 

 followed. The entire inflamed cutaneous surface of the trunk and 

 arm secreted a pale greenish, tenacious fluid, which left stiffened 

 spots in the linen. The skin of the scrotum, also, as well as that of 

 the lower extremities, presented the commencement of degeneration, 

 although only in a moderate degree. The patient experienced a 

 troublesome biting and itching over the whole body, especially at 

 night ; from this the insensible right arm only remained free. In 

 a few days, galleries and Acari were found. The introduction of 

 treatment for the itch removed the itching, the moisture, and the 

 eruption. The limbs acquired a normal epidermis, diminished in 

 bulk and increased in mobility, so that a complete cure may be 

 hoped for. 



After this digression we return to the description of the 

 disease in its ordinary course, and have still to speak of the 

 subjective phenomena, consisting in the sensation of biting and 

 itching, which lead to scratching, which again, as a fresh irri- 

 tation, increases the objective symptoms, renders the exudation 

 more abundant, distends the papillae and vesicles, removes larger 

 galleries from their positions, or, when the inflammation penetrates 

 more deeply into the cutis, produces red spaces round the pustules, 

 and even patches of inflammation under the galleries. In a still 

 higher degree, scratching leads to loss of blood, in consequence of 

 the bursting of blood-vessels which are at the bottom of the 

 exudation, to the desiccation of the latter into small, reddish - 

 brown, hard crusts, or small sores covered with scabs ; but very 

 reckless scratching produces furunculi and larger ulcers, which 

 are seen particularly upon those places which the hands can 

 easily reach (Hebra), whilst in cripples, who cannot scratch 

 themselves, and individuals who are confined in a strait-jacket, 

 or those who can command themselves sufficiently not to scratch, 

 they are wanting. 



Description of the Itch-mites. 



1. The adult female mite is visible with the naked eye, and 

 forms a roundish, dimly-shining, grayish-white corpuscle, ~ J"' 



3 



