The results obtained point to a consistent relationship between lipolytic activity and bacteriolytic power on tubercle bacilli.
The least bactericidal extract was lung extract; the most powerful was pancreas extract.
Liver, thymus and lymphatic glands were strongly bactericidal.
Other organs, suprarenal glands, pig and cat spleen, human and cat kidney, human and ox brain, ox thyroid, cat lung, ox bone marrow and ox pituitary glands were found to be bactericidal to a lesser degree.
The human skin extract examined for bactericidal properties was fatty and cloudy in appearance and exceptionally rich in esterases1.
Even if exceptional in its esterase activity this sample of skin bears out the relationship between lipolysis and bacteriolysis of tubercle bacilli in a striking way, as it was also extremely bactericidal.
No difference was noticed between bovine and human tubercle bacilli in susceptibility to any gland extract examined.
Other acid-fast bacilli, though on the whole less susceptible than tubercle bacilli to the influence of these extracts, were bacteriolysed by them. They were also killed by one lung extract (pig's) which contained an unusually large amount of olein lipase and which had no effect on tubercle bacilli.
I wish to express my thanks to Dr W. Cramer for his kind advice and encouragement, to Dr Cobbett for his kindly criticism, to Professor Shennan and Dr Miller for human material, and to Dr Wang for several strains of tubercle bacilli.
The expenses of this Research were met in part by a grant from the Earl of Moray Trust.