460 
DR. WILLEMS. 
cattle brokers make no variance in the price they pay for cows. 
If a number of castrated cows in good condition arrive mixed 
with steers, they are bought in at the same price per pound as 
the latter, but, if with a lot of natural cows, no distinction is 
made. Of course this is all wrong, but the castrated cow is not 
a staple article in the United States market as yet, and until she 
becomes such, so that the butchers may be able to realize her in¬ 
creased value, there will be no regular rates of exchange for such 
animals. Furthermore, they can never become a staple article 
until the educated Veterinarians practice ovariotomy, thus gradu¬ 
ally withdrawing it from the hand of the empirics, thereby de¬ 
creasing the mortality following tne operation, and thus illustrat¬ 
ing to the agricultural world what practical benefits may be 
derived from its universal introduction. 
NEW RESEARCHES UPON PLEURO-PNEUMONIA AND 
ITS PREVENTIVE INOCULATION. 
By Dr. Willems. 
(Continued from page 422 .) 
III. 
Can pleuro-pneumonia when inoculated be communicated to 
non-inoculated animals kept in the same sheds ? 
The answer must be negative. This disease is transmissible 
only by contagion, by inoculation of pathological products, and 
by re-inoculation. 
I have successfully practiced re-inoculation with secondary 
virus. The official commissions of the Netherlands and many 
other operators have done the same. 
Mr. Lenglen, of Arras, reported that he had inoculated 1,000 
subjects with secondary virus, obtained by an incision at the tail 
of an inoculated animal, and he adds—“ To-day I used a virus of 
the twenty-fifth generation, which has lost none of its protective 
virtue.” 
