Armstrong – Table of Contents

Professor of Pathology, College of Medicine, Ohio State University performed
investigations to determine the nature of the “poison” and the probable bacterial organism
that produced it. Small amounts of brine or a suspension of olives proved lethal when
injected into guinea pigs. A jar of olives of the same brand and shipment as those at the
banquet furnished material for controlling these experiments. The control animals
remained well. The test brine also proved fatal when fed to guinea pigs. Brine passed
through bacterial filters regularly killed the animals. The same filtrate heated to 80C for
30 minutes proved to be harmless.
Armstrong and co-authors next tested the olives and brine for “anaerobic spore bearers”.
They inoculated the test material into appropriate bacteriologic media, heated the mixture
at 60C for 60 minutes, and incubated the mixture under anaerobic conditions at 37C and
at room temperatures. Within 2 days the tubes at 37C showed evidence of bacterial
growth, and the tubes at room temperatures showed growth in 5 days. Growth could be
transferred from these initial tubes to subsequent tubes, and the organisms from initial
tubes and transfer tubes were identical. The germ isolated showed the appearance,
anaerobic growth, and biochemical reactions consistent with Bacillus botulinus (now
Clostridia botulinum). “Sisco of the Harvard Laboratories” (9) confirmed the
identification. Armstrong and associates mixed ripe unspoiled chopped olives in tubes
along with brine of the same brand as the original jar adding no additional ingredients.
They autoclaved these tubes at 15 pounds pressure for 30 minutes, cooled the tubes
rapidly, inoculated the mixture with the test brine and grew the mixture under anaerobic
conditions as before. After 3 days they detected growth as indicated by gas formation and
bubbles accumulating in the ground olives at the bottom of the tubes. The bacterium