ON THE PATHOLOGY OF SHEEP-POX, past | 
on referring to authorities, that in those countries in which 
inoculation is carried on on a very large scale with a view to 
the protection of animals from attacks of the disease, it is 
extremely rare to meet with instances in which secondary 
pustules present themselves in addition to the primary one 
at the seat of insertion ; it was therefore necessary to employ 
some other method. 
I fortunately succeeded completely in producing a general 
eruption by introducing the sheep-pox virus into the circu- 
lating blood. Having diluted the liquid with from fifteen to 
twenty times its bulk ofthesolution of chloride ofsodiumalready 
referred to, I injected it directly into the external mammary 
vein of ahealthy sheep. At the same time that this was done 
I inoculated the animal in the usual way, making in all ten 
insertions. My object in employing both methods simul- 
taneously was, that I might utilise the animal to the utmost. 
I was desirous on the one hand to induce a general infection, 
and thereby a general eruption; and on the other to obtain 
an additional supply of primary pustules for the completion 
of the investigations I had already made. I also thought it 
of great importance to compare the anatomical characters of 
the primary and secondary eruptions in the same animal. 
The injection and inoculation were performed on the Ist of 
April; the primary papules made their first appearance on the 
4th. On the 7th several small secondary papules appeared on 
the lips and around the mouth, and increased rapidlyin number 
during the succeeding three days. At the same time the 
eruption extended to other parts of the body, but the papules 
were most numerous in the axilla and on the belly. It is to 
be noted that the interval of time between the appearance of 
the first and last papules of the secondary eruption was con- 
siderable, so much so that the pustules on the lips had already 
formed crusts at the time that the eruption was first visible 
in other parts. In this case, as in the others, the primary 
pustules were from half an inch to an inch and a half in dia- 
meter; most of the secondary ones did not exceed a quarter 
of an inch, but there were a few of those which appeared 
latest on the chest and belly which measured half an inch 
or more. 
Section I].— Microscopical characters of Sheep-pox virus.! 
Clear lymph, which had been kept for several days in a 
sealed capillary tube, was diluted with thoroughly boiled half 
per cent. saline solution. One portion of the diluted liquid 
having been reserved for further experimental inoculations, 
' The description relates to a specimen of lymph sent by Prof. Colin. 
