t7t DADD'S VETERINARY MEDICINE AND SURGERT. 



The Skin Diseases of Domestic Animala. 



A celebrated writer on the diseases of the skin of domesticateti 

 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 feeding qualities of stock are affected by them. Thia 

 arises from the little progrc;-?- 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 historv have been drawn from the 

 traditionary philosophy of our forefathers, and not from actual ex- 

 amination, cither 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 zoological science, to fill 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, beiore 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 thf 

 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 by 

 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 

 farmer, so as to profit by its deductions. These were principally 

 oontined, it will be seen, to scabies and setrus in sheep and othef 



