587 
Home Extracts. 
Experiments made on Sheep with the Insect, the Ichor, 
the Scurf and the Blood of Sheep 
AFFECTED WITH THE SCAB. 
By Herhwig. 
The following report of experiments made on sheep having the 
scab (for which we are indebted to our friend, Mr. Gloag) has been 
translated by Dr. Whiting, of Lynn, from the German, and, we 
think, will be found useful and instructing to our readers. We 
shall continue it monthly. 
Although Linnaeus ( Exanthemata Viva — Upsal, 1757) has al- 
ready made mention of the insect which causes the scab, and Wich- 
man in his “ Causes of the Scab,” published at Hanover, 1786 and 
1791, has already expressed a conjecture that the scab in sheep 
and the itch in man are similar diseases, and that both are caused 
by an insect; and although Videbantt, in his “Practical Treatise on 
the Treatment of the Scab,” published at Stettin, 1 790, has clearly 
expressed his view that an insect is the cause of the scab ; yet, 
really, the honour of proving satisfactorily the presence of the in- 
sect, as well as shewing its natural history, its distinguishing cha- 
racter, moreover, the situation it occupies and the way in which 
the disease is propagated, is due to Waby, the veterinary professor, 
at Wurtemburg, who has given his experience in the publication 
entitled “ Nature and Treatment of the Scabbed Sheep,” published 
August 1812. In this work he says, at page 47, upon the man- 
ner in which the insect causes the scab, that he often repeated the 
experiment of placing upon the hide of sound sheep some of the 
insects, and they immediately began to bore into the skin, and the 
scab fully manifested itself ; that the disease so produced got well 
spontaneously when the experiment was performed only with the 
male insect ; and, on the contrary, it continued obstinate, and 
spread itself more and more, through the production of young in- 
sects, when the insects were of both species, or females impreg- 
nated ; and, that when the disease was so produced, it could be 
entirely cured by removing every insect from the infected sheep. 
It is fully acknowledged (at least by the German veterinary 
surgeons) that these observations are of the highest interest, both 
for shewing the nature and cause of the scab, as well as for point- 
ing out practically the most likely way of curing this evil. More- 
over, in a political point of view, it is of great importance to know 
the time likely to expire between the period when sheep may have 
