Annual Report for 1908 of Royal Veterinary College. 293 
immunity is not permanent ; and, while it is not yet possible 
to say precisely how long it lasts in a serviceable degree, there 
is reason to believe that it may have almost entirely disappeared 
a year after the operation. 
Lastly, an important fact in connection with this method 
of protecting cattlfe against tuberculosis is that it cannot be 
employed in the case of pregnant heifers or milch cows, 
because it has been found that the tubercle bacilli present in 
the vaccin may persist in the animal’s body for months after 
the operation, and possibly some of them might be passed out 
with the milk. 
Where the circumstances permit of its employment, the 
best method of freeing a herd from tuberculosis still is to 
test the whole of the animals with tuberculin, and effect a 
permanent separation (in premises widely apart) between 
those that react and those that do not. Needless to say, this is 
a method which involves much trouble and expense, and in 
many cases it is on that account impracticable. In valuable 
pedigree herds, apart from the question of trouble and expense, 
it is generally considered impracticable because it requires the 
calves to be separated from their dams as soon as they are 
born. It is in such herds that the protective inoculation of 
the calves might be adopted with most advantage. Although 
the “ vaccin ” has to be injected into one of the jugular veins, 
the operation is one which any competent veterinary surgeon 
can undertake, and it has been decided to supply the vaccin, 
free of charge, from the Research Laboratory at the Royal 
Veterinary College, for the vaccination of calves belonging to 
members of the Society during the current year. 
Cases of Poisoning in Animals. 
It has been thought of interest to include in the present 
Annual Report the following notes, which Dr. Lauder has 
supplied, regarding analyses in suspected cases of poisoning 
during the last few years. 
With the smaller animals — foxes, dogs, &c. — strychnine has 
been found to be by far the most frequent poison. From the 
standpoint of the agriculturist, however, more importance 
attaches to poisoning of horses and cattle. If one may judge 
from the cases sent to the College, vegetable poisoning among 
these is rare, but during the past five years cases of poisoning 
by yew and by hemlock have been encountered. 
Taking averages of cases in horses and cattle examined 
during the last three years, lead and arsenic were found in the 
following percentages : — 
Lead 
Arsenic 
Cattle 
25 
20 
Horses 
0 
16£ 
