The daily morning journal and courier., 1903-04-30
THE PROBLEM or DISEASE
 IMMUNITY. ~

r The unWarranted slmpllncatlon or the
 problem of immunity led to a similar misrepresentation of the theory and practice of serum therapy. The ex-
 tremely complex subject is made to ap-
 pear so simple, indeed, that schoolboy can fathom it. Here is the whole
 thing in nutshell. We want specific remedy for a certain infectious disease.
 We inject the specific germ or its pro-
 ducts into horse, and in due time tap
 that animal for it's health-restoring serum. The latter, containing the specific antidote, counteracts the toxins in the body. What could be simpler than this universal formula And if serums can be obtained to neutralize the toxins generated by pathogenic germs why not have serutls to counter
 act the effect of alcohol, morphine, and what not? Indeed, the range appears to be almost boundless, We may per-
 haps, have also serum for the cure of laziness, if the germ of that pandennic affection over be discovered. And, if. not, 1t need not disconcert us either for we might find the laziest animal in the world, grind 1t up, and inject the ex- pressed juice into a horse, the serum of which will cure laziness. Such are the absurdities which may result from a free interpretation of the highly conn piex theories of immunity. While it is. true that some such simple process takes place in the production of anti diphtheritic serum, this IS at present. the only instance of the simple work ing of biological forces. Antitetanic se- rum. practically the only other tntitox- ic fluid, is similar in it's mode of action. although the latter seems to be gov- erned by, somewhat different laws of bi- ochemical affinity. On the other hand. the serums obtained after ifranuniza- tion with germs which do not possess soluble poisons, and they are in the majority, are most complex and baffie our understanding Anti-streptococ anti-pneumococcic and similar serums are unknown virtues and uncertain in their action. It cannot even be said that their rightlto existence as thera- peutic agents has been definitely estab- lished by laboratory experiments. Each of the micro organisms in ques- ton presents wide variations in patho- genicity, the disease-p producing power varying from a local abscess to gene- ralized fatal septicemia.. or pyernia.
 There is no telling what a given mi cro-organism will do in a given case, and the only way we have of judging of the pathogenic power of a given germ, belonging to this group, Is q, pos- teriori, i. e.. after the disease has erl- tered into an tdvanced stage. At such times any serum would practically be worthless Besides, there IS no way of testing the strength of such a serum. Laboratory animals differ widely in their susceptibility, and the establish ment of standard unit is an irapossi- bility. In the irnmuni2ation of horses for the production of the serum, as well as in the experiments on laboratory am irnals, the results obtained by various investigators are so discrepant that even an approach to uniformity is out of the question. Tha best results ob- tained by some investigations with al1tistaphylococcic serum, for instance, represent pratective value of twice the minimum fatal dose Such g se- rum, when used on man, would have to be employed ill doses of sbo- 700. cc. (Petersen.)
 The general principles underlying passive immunity have been satisfac- torily formulated, but the details are still obscure, and, until experiments in the laboratory establish with absolute certainty the therapeutic value of a given serum the physician is not Jus- tified in jumping at conclusions. We can well afford to bide our time and let the scientist clear up the path for us to, follow Nothing will be accom- plished by the wild rush after new Tangled specifics. adelphia Medical Journal. s75