DISEASES OF THE SKIN AND SUB-TISSUES. 281 



hatched under certain cutaneous affections, thus accounting for 

 spontaneous cases differently from the atmospheric distribution of 

 eggs. Hence the reason why sulphur and mercury are taken, 

 internally as well as externally, to get rid of the disease. But 

 this sanguiferous doctrine of distribution is more difficult to re- 

 concilc with entomological science than the atmospheric one. 



Contagion by direct contact of clean animals with diseased, or 

 where the former enter foul ground, will be difficult to avoid so 

 long as the commerce of live farm stock is conducted as at present ; 

 for diseased animals will be sent to market, although contrary to 

 the spirit of the law, thus not only communicating the disease to 

 all they come in contact with, but also infecting the market-place. 

 According to the experiments made by Mr. Simonds, acari left 

 upon a post, hurdle, or hedge by a scabbed beast will survive 

 for fourteen days, and at the end of that time lay hold of any 

 animal coming in contact with it, and thus communicate the dis- 

 ease ; consequently our weekly and fortnightly markets are little 

 better, during the warm months of summer, than nests for pro- 

 pagatiug malignant parasites. It would be well, then, if very 

 stringent statutes were enacted, confiscating all diseased animals 

 offered for sale, and that microscopical examinations were enforced 

 in all suspicious cases, so as to guarantee its healthy operation. 

 It will thus be seen that the means for preventing contagion may 

 be summed up in two words — improved management. 



At a very early period in our history, acarus scabiei was much 

 more common among our forefathers than among their posterity 

 of the present day. The change which has taken place is obvi- 

 ously attributable to progress in dietetics, clothing, and medicine ; 

 and among our domesticated animals it is no more than reasona- 

 ble to conclude that similar causes will produce similar effects. 

 In point of fact, improved management has already greatly re- 

 duced the prevalence of scabies among both our herds and flocks, 

 thus holding out every encouragement to persevere in obtaining 

 further progress. There is, perhaps, no branch of husbandry 

 where greater advances can be made than in cattle-cookery, house- 

 hold accommodation, including grooming, etc., and medicine ; and 

 when we contemplate how much cutaneous diseases are dependent 

 on management in each of these three respects, it were difficult to 

 estimate what influence further improvements in them may tave 

 *m the disease in question."' 



