A review of the literature reveals but one article bearing directly on
the subject of the cause of ham souring.
In June, 1908, Klein[1] published in the London Lancet an article
on “miscured” hams. He describes a miscured ham as one which has a
distinctly putrid smell, and the tainted areas he describes as varying
in color from a dirty gray to a dirty green, the muscular tissues in
the strongly tainted areas being swollen and soft, or jelly-like. From
such hams he isolated a large nonmotile, nonspore-bearing, anaerobic
bacillus which he calls _Bacillus fœdans_. He cultivated the organism
on different media and obtained from the cultures a putrid odor
resembling that of the ham from which the culture was obtained, but
did not attempt to produce tainting by injecting sound hams with the
bacillus.
[1] Klein, E. On the nature and causes of taint in miscured hams. The
Lancet, vol. 174, London, June 27, 1908.
While there can be little doubt that Klein’s bacillus was the cause of
the tainting in those hams which he examined, the proof would certainly
have been stronger had he injected sound hams with cultures and thus
proven that he could reproduce tainting experimentally by means of his
bacillus. Klein examined only dry-cured hams and does not state the
temperature at which they were cured. He fails to offer any explanation
as to how the bacillus gained entrance into the hams.