27& DADD'S VETERINARY MEDICINE AND SURGERY. 
Tue Skin Diseases OF DoMESTIC ANIMALS. 
A celebrated writer on the diseases of the skin of domesticated 
animals, thus discourses on the subject: 
“Few topics have engaged the attention of the successful breeder 
of our improved domesticated animals more than skin diseases pro- 
duced by insects, in consequence of the manner in which both the 
breeding and feedir z qualities of stock are affected by them. This 
arises from tl-e little progres~ scientific inquiry has experimentally 
made in the physiology of these tiny parasites by means of the 
microscope, and the consequent paucity of reliable scientific works 
on the subject. Hitherto half the conclusions of our veterinary 
surgeons relative to their natural history have been drawn trom the 
traditionary philosophy of our forefathers, and not from actual ex- 
amination, either with the eye of the modern physiologist or mor- 
bid anatomist; while our entomologists have had too much to do 
to overtake the branches of zodlogical science, to 4] their cabinets 
with specimens of the class in question—a class far more varied 
than the kingdom itself, every different race of animals being not 
only infested with a different brood of insects (mites), but almost 
every organic substance, animal and vegetable. 
A very superficial acquaintance with these facts must convince 
the reader of the importance of the lecture on this subject, de- 
livered by Professor Simonds, berore the council of the Royal 
Agricultural Society of England, accompanied with drawings, 
exhibited on the wall, and specimens under his microscope. The 
former, drawn to a greatly magnified scale, illustrated, in a very 
conspicuous manner, the different stages of vitality, from the ovum 
to the insect, in all the vigor of matured life. But to us, and 
several other members who examined them, the latter appeared 
the most interesting, as nothing can exceed the fidelity with which 
the microscope exemplifies Nature, though all but invisible to the 
naked eye, confirming, in the most satisfactory manner, the sound: 
ness of the conclusions at which the Professor arrived, differing, 
as they did, in many respects, from those hitherto drawn, both y 
veterinary surgeons and entomologists. 
Referring to the report of Mr. Simonds’ first lecture, the task 
which devolves upon us is to apply it to the daily practice of the 
fariner, so as to profit by its deductions. These were principally 
confined, it will be seen, to scabies and etrus in sheep and other 
