CONTAGIOUS BOVINE ABORTION.                                273

ampoule of Nator B after 30 days and a second after 45 days of gestation and
from the commencement of the fifth month a subcutaneous injection behind the
shoulder of 5 c.c. of a 5 per cent. aqueous solution of carbolic acid once every fifteen
days until calving is accomplished.

Leuthold [1920] reports favourably on the therapeutic value of syrgotral which
is an odourless and tasteless 1-6 per cent. aqueous solution of syrgol, a solid sub-
stance containing 20 per cent.silver in the form of colloid oxide of silver and of
colloidal silver. The drug is administered per os and the best results are obtained
when syrgotral is administered before the animals are bred and during the first
two months of pregnancy or during the seventh, eighth and ninth month of
pregnancy.

Graham and Thorp [1930] experimenting with acriflavine, trypacrin " A"
(a compound of gentian-violet and neutral acriflavine), tryparsamide, colloidal
carbon and iodine in the form of alkali hypoiodite "Farodine", found that while
acriflavine, both neutral and acid dyes, and to a less extent trypacrin " A"
possessed some bactericidal action on Bacillus abortus suis Traum in vitro, these
and the other drugs exerted no germicidal action on the organism in vivo in that
they failed to alter the blood serum agglutinin titre of abortion infected cows.
Acriflavine, trypacrin "A", tryparsamide and colloidal carbon were administered
intravenously and alkali hypoiodite " Farodine " intramuscularly.

Gwatkin failed to note any beneficial results following the use of formaldehyde
and mercurochrome in artificially Bacillus abortus infected rabbits when adminis-
tered intravenously in 3 per cent.and 1 per cent.strengths respectively.

Ziemann [1921] claims to have cured cases of undulant fever by intravenous
injections of collargol and to have tried the. drug in contagious abortion infected
herds but does not give any results.

Other drugs that have been unsuccessfully tried include neoarsphenamine and
sodium cacodylate administered intravenously, pyridium and butyl chloride per os,
thionin intravenously and by the mouth and chloroform vapour viâ the teat canal.
Neosalvarsan, mercuric iodide and methylene blue have likewise been found to be
of no value.

From the above summary of the results hitherto obtained, it will be seen how
difficult it is to assess the relative merits of the various therapeutic agents that have
so far been tried in the absence of more extended and properly controlled trials,
for while in the case of some, conflicting findings have been recorded with regard
to the efficacy or otherwise of the others we have the testimony of individual
workers alone to rely upon. The disease has proved so ruinous and intractable