722 THE CONTAGIOUS DISEASES (ANIMALS) ACT, 1869. 
alisy but it is among calves and lambs in particular that the 
more serious consequences follow. Microscopical investigations 
have made us familiar with the nature of the disease induced 
in the lungs, and also taught us much of the natural history 
of the lung- worm. They have not, however, cleared away 
all the difficulties which beset the subject ; and so much of 
the natural history of the worm as belongs to its existence 
out of the body of its host, and the way in which it finds its 
entrance into the air-passages, remains to be satisfactorily 
explained. This part of the subject is of the greatest import- 
ance, because it points to the means that should be employed 
to prevent the pneumonic disease. Within the body many 
parasites are, to a great extent, unassailable, or, at any rate, 
we cannot effect either their expulsion or death before they 
have laid the foundation for disease, which will go on despite 
the best-directed means of cure. To some extent this is the 
case with the parasites in question, and hence the inutility of 
treatment in many cases, especially those which have been 
neglected in their early stage. Our present knowledge of the 
natural history of the lung-worm warrants the conclusion that 
the embryos are parasitic to many of the grasses, particularly 
those making up natural pastures. Lambs kept rigidly from 
these and from old layers which have been fed previously with 
sheep, are found to escape an attack, even in districts and in 
years when others differently managed fall a sacrifice to the 
disease. The principles of cure consist in causing an expulsion 
of the parent worms — those which accumulate in the wind- 
pipe and large bronchial tubes — and destroying the embryos as 
they escape from the ova, which are present in vast numbers 
in the air-cells of the lungs ; and also in arresting the 
pathological changes by strengthening the constitution of the 
animals by a free use of tonics, generous diet, and protection 
from all vicissitudes of weather. 01. turpentine, with tinct. 
of assafoetida, conjoined with glycerine, will often effect the 
first object ; and sulphate of iron, powdered gentian, bark, 
ginger, and allied agents, the second, so far as therapeutic 
treatment is concerned. 
THE CONTAGIOUS DISEASES (ANIMALS) ACT, 
1869. 
“ Return of the Number of Foreign Animals brought 
by Sea to Ports in Great Britain, which on inspection on 
landing, within the Month of August, 1871, have been 
found to be affected with any Contagious or Infectious 
