ABSTRACTS
171
or absence of bacterial cells in the product has no effect on the potency. It is shown that the
amount of growth, the production of aggressive substances and the pathogenicity of a blackleg
culture are independent. Virulent blackleg cultures consists of three parts: (1) living bacterial
cells, (2) aggressive substances or products of growth produced during the development of cultures
of Clostridium chauvaci and (3) a lethal substance or specific activity of the virulent bacterial
cells. Potent blackleg products should have a potency of at least 20 aggressive units per dose. By
the use of certain mineral salts and of the proper amount of formaldehyde, blackleg filtrates and
bacterins having potencies of 130 and 260 aggressive units can be produced. Formaldehyde inhi-
bits the agglutinogen but increases the activity of the protective antigenic complex. (Reprinted from
Journal of the American Veterinary Medical Association, New Series, Vol. 30, No. 6, November,
1930.)
Eleventh International Veterinary Congress, London, August 4th to 9th, 1930.—
(From The Journal of Comparative Pathology and Therapeutics, Vol. XLIII, Part 4,
December 1930.)
RESOLUTIONS.
At the closing meeting of the Congress, held on Saturday, August 9th, 1930, the following
Resolutions were passed.
I. Official Languages.—That for future Congresses the official languages remain as at present,
viz., English, French and German, but that, if found possible, the summaries of reports may be
translated also into Italian and Spanish.
II. Date and place of Next Congress.—That the invitation of the American Veterinary Medi-
cal Association for the next Congress to be held in the United States of America, probably at Boston
in the year 1934, be accepted.
III. Foot-and-Mouth Disease.—That, in the opinion of the Congress:—
(a) The establishment of the existence of a plurality of viruses foot-and-mouth disease is of
the highest significance in relation to the epizootiology of the disease and to methods of
active and passive immunization.
(b) It is highly desirable that in all countries the type of virus present should be determined
in all primary outbreaks.
(c) In respect of disinfection, it should always be remembered that both the diseased animals
and the buildings constitute a serious danger in the spread of the disease.
(d) The most efficient disinfecting agents are moist heat and sunlight and, of chemical
agents, potassium and sodium hydrates and formalin.
(e) The value of passive immunization has been established, and its use in practice in favour-
able circumstances is to be encouraged.
(f) It is highly desirable that all possible efforts should be made to discover an efficient method
of active immunization.
IV. Infectious Abortion of Sheep, Cattle and Swine.—(a) That scientific investigations regard-
ing contagious bovine abortion are essential in all civilised countries, particularly for the purpose of
controlling the disease, the preparation of an effective method of immunization, the elucidation of the
rôle of Bacterium abortus Bang as a cause of disease in man, and determining the relationship
between the disease caused by this organism in man and Malta fever.
(b) That, in view of the very widespread occurrence of infectious abortion of cattle in all civilised
countries, an international scientific investigation should be carried out, and that such an investi-
gation would come within the purview of the office International des Epizooties de Paris.