650 TRANSACTIONS OF SECTION I. 
The effects of changes in the environmental conditions were also studied, 
and the results will be given when the paper is published in extenso. 
9. Report on the Electrical Phenomena and Metabolism of Arum 
Spadices.—See Reports, p. 315. 
TUESDAY, AUGUST 31. 
Joint Discussion with Section B on the Chemistry of Food.—See p. 459. 
The following Paper was then read :— 
Observations on the Micro-organisms of the Gaertner Group (‘ Meat- 
poisoning Bacilli’), with special reference to their Agglutination, 
Reactions, and their Behaviour on Coloured Substrata. By Pro- 
fessor EK. J. McWeeney, M.A., M.D., D.P.H. 
Professor McWeeney referred briefly to the economic aspect of the 
subject. Outbreaks of this sort of illness are not uncommon, and are often 
described as cases of ptomaine-poisoning. They are caused by the ingestion 
of meat that had become infected with micro-organisms of which the 
prototype was isolated by Gaertner from an outbreak at Frankenhausen 
in the late ’eighties of the last century, and which are therefore known 
as the Gaertner group. They are all short bacilli endowed with extremely 
active mobility. They do not liquefy the nutrient gelatine, and form, 
colonies on it closely resembling those of the ordinary intestinal organism, 
bacillus coli communis. They differ from bacillus coli, however, and 
resemble the typhoid bacillus in their inability to ferment lactose or 
form indol. Of Gaertner bacilli there are at least two types, the original 
or true Gaertner, which was isolated by Van Ermengem and his pupils 
from the outbreaks of meat-poisoning at Rumfleth, Hanstadt, Morseele, 
&c., and that known as the Fliigge-Kaensche, or Aertryk type. These 
bacilli are also closely allied to, if not identical with, those causing a 
disease resembling typhoid fever and known as paratyphoid—a disease 
which is often due to ingestion of specifically infected articles of food. 
It would seem as though, when small numbers only of the specific bacilli 
are present in the infected meat, a general invasion of the organism took 
place, accompanied by a febrile reaction with a definite incubation period 
and the symptom-complex known as paratyphoid fever. When, on the other 
hand, the meat contained a large dose of the virulent metabolic products 
of the organism, the symptoms came on at once, or after the lapse of a 
few hours, and speedily ended in death or recovery. In no case could the 
term ptomaine poisoning be considered applicable to these cases, as the 
word implies putrefaction, which is certainly neither an essential nor 
even a usual condition of the meat in these cases. It is often quite fresh. 
After briefly referring to the main features of the disastrous outbreak 
of meat-poisoning at Limerick, which he had occasion to investigate last 
year, the author said that the conclusions to which he had been led by 
his study of the bacillus of meat-poisoning were as follows: 
1. The particular strain or race of Gaertner bacillus isolated by him 
from the Limerick case is of high virulence for rats and mice when 
administered with food. Rabbits succumb to subcutaneous injections not 
merely of the living bacillus, but also of old cultures heated to 65” C. 
Very old (nine months) cultures, however, are found to have lost their 
virulence. A calf aged four months was killed in seven hours by the 
injection of 20 cubic centimetres of culture-fluid into the jugular vein. 
