BOTULISM OR ALLANTIASIS 523 
mented. The acid formed is partly valeric;, partly butyric and ])artly 
lactic, and the gas consists ])rincipally of carbon dioxide and hydrofjen. 
Neill and Fleming' have isolated both a maltase and a lipase: the former 
is endocellular, the latter exocellular. 
The most important product of B. botulinus, however, is a potent 
extracellular toxin which is readily prepared by growing the organisms 
anaerobically in broth at 25° C. for two weeks. The broth is filtered 
through sterile porcelain filters, preferably in an atmosphere of h\(lro- 
gen, and the toxin is found in the filtrate, from which it can be pre- 
cipitated by the addition of a 3 per cent aqueous solution of zinc 
chloride in the proportion of 2 parts of zinc chloride to 1 of broth. - 
The toxin deteriorates rather rapidly if it is exposed to sunlight or 
oxygen. If it is kept in the dark in sealed, full bottles and kept cool 
it retains its potency for some months. It keeps still better in the dried 
state in the absence of light and moisture. Heat promptly inactivates 
.it. An exposure to 50° C. for three hours, or at 80° C. for thirty 
minutes utterly destroys its potency. It is not, however, destroyed by 
putrefaction or by gastric digestion, a point of great importance 
clinically, for poisoning with the toxin of B. botulinus almost always 
results from its absorption from the intestinal tract. The toxin has 
been identified in meats in which the organisms have grown. The 
suspected material is macerated with water^ in a cool, dark place, 
filtered through porcelain, and the filtrate is found to contain the toxin. 
The toxin also is produced when the organisms grow under proper 
conditions in vegetables.* The toxin causes death when injected sub- 
cutaneously, or fed to experimental animals. There is a latent period 
which elapses between the time of administration of the toxin and the 
appearance of symptoms. This latent period, when large doses are 
administered, is typically from twelve to twenty hours; with moderate 
doses it is longer; two to three days, or even up to four or five days. 
One-thousandth cc. of broth containing toxin injected subcutaneously 
into guinea-pigs usually kills them in three to four days; 0.1 to 0.5 cc. 
of the same toxin absorbed in bread and fed to rabbits results fatally 
in from four to six days. Dack^ found the toxin in the blood of rats 
three hours after its introduction into the alimentary canal. It is toxic 
for man, white rats, mice, kittens, guinea-pigs, chickens, turkeys, 
rats, dogs and even monkeys in relatively small doses. In larger doses 
it is also pathological for cats and doves. Dickson" has found that 
"limber neck" is a characteristic lesion in chickens which have eaten 
food containing the toxin of B. botulinus. The toxin is bound by the 
gray matter of the central nervous system. C'holesterin, lecithin, and 
1 Jour. Exp. Med., 1927, 45, 937. 
2 Brieger and Kempner: Deutsch. med. Wchnschr., 1897, 23, 521. 
3 It is desirable to perform this operation under conditions as nearly anaerobic as 
possible. 
* Landmann: Hyg. Rund., 1894, p. 449. Dickson: Monograph No. 8, Rockefeller 
Inst, for Med. Res., July 31, 1918 (full bibliography to 1918 in this publication). 
^ Jour. Infec. Dis., 1926, 38, 174. « Loc. cit. 
