koch’s method with tuberculosis 
77 
be added, of treatment. With this in view, it may be well to 
trace some of the leading landmarks in the gradual discovery 
of those poisonous products now known as enzymes and 
ptomaines. Strangely enough, the belief in chemical poison¬ 
ous products antedates by many years the recognition of liv¬ 
ing germs as the cause of disease. Poisoning by decompos-. 
ing meat and fish had long been a familiar occurrence when, 
early in the eighteenth century, Haller experimented by 
injecting Avatery extracts of putrid material into the veins of 
animals, and found that death resulted. In 1820, Kerner, in¬ 
vestigating the question of poisonous sausage, came to the 
conclusion that the toxic principle was a fattA r acid combined 
with a volatile principle. Others pursued similiar investiga¬ 
tions, but it was only in 1856 that Panum positively demon¬ 
strated that the poison Avas a chemical product, which was 
soluble in water and capable of filtration from other and 
insoluble bodies. He found in the decomposed flesh of the 
dog a toxic product, soluble in Avater, insoluble in alcohol, 
non-volatile and indestructible by boiling. Of this chemical 
poison, 0.012 of a germ proved nearly fatal to a small dog. 
Panum, however, Avent further and succeeded in isolating 
another chemical poison from the putrid meat which was 
easily separable from the first by the fact that it was soluble 
in alcohol. This alcoholic extract injected into a dog’s jugu¬ 
lar threw him into a sleep for twenty-four hours, after which 
he awoke in apparent health. To Panum, therefore, we OAye 
the first recognition of two classes of products of bacteridian 
growth, which act on the animal system as chemical poisons 
and Avhich have now come to be recognzied as ptomaines 
(cadaver), which are basic or alkaloidal and toxic albuminoids 
of a non-basic nature. 
Following Panum, came Weber, Hemmer, Schwenninger, 
Bence-Jones, Depre, Marino-Zuco, Bergmann, Schmiedeberg 
and others, and the true basic or alkaloidal nature of the pro¬ 
duct which is precipitated by alcohol, established. 
The poisonous property of these chemical products, 
even after a prolonged exposure to heat, which must have 
killed any living germs, for a time antagonized the theory of 
