Practical Experiments on the Air-drainage of Land. 343 
and similar experiments is, that drains two feet deep, even at five 
yards apart, with air-drains to facilitate evaporation, &c., are not 
of suHicient depth to secure good drainage, yet I am quite con- 
viced that tliev are more than equal to drains two feet six inches 
deej) without such auxiliaries. Thus, by the simple and inex- 
pensive ])lan of introducing my air-drains into lands drained by 
present insufficiently deep drains, the superior advantages of 
deeper drainage are, as has been shown, in some degree ac- 
quired. 
Manthorpe Lodge, Grantham, Lincolnshire, 
30th September, 1 848. 
XVII. — Pleuro- Pneumonia among Cattle. By George Waters, 
Jun., M.R. Coll. Vet. Surg. Corn Exchange Hill, Cam- 
bridge. 
Prize Essay. 
The present epizootic disease, designated " Pleuro-pneumonia '' 
from 7rX£y§«, the side, or membrane enveloping the lungs, and 
irvsvixuv, the lungs, from its being confined principally to those 
parts — first appeared in this country about the year 1841 — 
previous to which period it had existed and committed great 
ravaffes among the cattle in Ireland, and on the continent — and in 
England a very great proportion of the whole number of cattle 
which have been afFecte<l have died. 
It Is a rare thing for any epizootic disease to rage alone — that 
is, without being preceded or followed by some other. It will be 
remembered that the vesicular epizootic, which first appeared here 
about the year 1S39, was the forerunner, and is to this day the 
companion of the present pleuro-pulmonic disease ; but the ulti- 
mate consequences of each disorder differ as widely as they do in 
character. The vesicular ej)izootic, on the one hand, spared but 
few animals from its attack, and was seldom if ever fatal ; whereas 
on the other, the disease in question affects few in comparison, but 
those in so dangerous a manner that but a very small proportion 
of those affected recover. 
I shall first attempt a description of the disease, treating 
slightly the premonitory symptoms — mentioning those only which 
may be referred to the organs of respiration more especially, I 
am induced to do this, because I shall have occasion, in following 
out the order proposed by the committee of the Royal Agricul- 
tural Society of England with reference to several points con- 
nected with the disease, to treat of the "premonitory symptoms" 
at greater length. 
