COPIRIGB'l'BD by PHILLIS ALLES 1949 AMERICANS AND THE GERM THEORY OF DISEASE Phyl lis Allen A Dissertation in History Presented to the Facultyof the Graduate School of the Universityof Pennsylvania in Par­ tial Fulfillmentof theRequirementsfor thedegree of Doc­ tor of Philosophy. August, 1949 Approved by Cvcrw.AI\T? W Ju,�. ;;,?,�ff::�� M L 1-Hs+. Qu) 11. I A4��£L TABLE OF CONTENTS J Cf'A/9 Preface Chapter 1. IntroductoryNote Theories of the Causation of Disease in theEarly 2. N�eteenth Century 3. The Contagium� Theory 4. American Animalcullsts @ The Germ Theory of Disease in the Mid-Century 6. Controversy over the Germ Theoryin Europe 7. The Germ Theory Comes toAmerica 8. Some Factors in theEarly AmericanNegiect of Bacteriology PREFACE This study was origtnally begun as a biography of 1obnKearsley Mitchell, but the background of Mitchell's cryptogamous �eory proved to be so interestingand of such signliicancethat a much fuller study of thisfield was indicated. The subject of Americananlmalc � hypo­ theses and their relation to the later development of medical bacteriology has been discussed brlefiy in a number of studies, and acknowledgement of my indebtedness to thesewill be noted in the citations. No systematic account of the early Americaninterest in the germ theory of disease has hithertobeen written;and the present study has been preparedwith this end in view. A considerable amount of the material in chapters two andfour was published in two articles in 1947. The first and longer study,'"Etio­ loglcal Theory in A�erica Prior to the Civil War,• appeared in the 1ournal of the History of Medicine and Allied Sciences, VoL II, No. 4, Autumn, 1947, and parts of it are presented here withthe permission of the publisher, Mr. Henry Schuman. AJ1 analysis of theAmerican theories of the animalcular type, "Early American AnimalcularHypotheses," appeared in the Bulletin of the History of Medicine, Vol XXI, No. 5, Sep­ tember-October, 1947, and some data in it ar� presented with the per­ mission of the editor, Dr. Owse� Ternki1'- I wish to thank theAmerican Council of Learned Societies for a Pre-Doctoral Fellowship, and the University of Pennsylvania for a 11 Bloomfield Moore Fellowship, which enabled me to continue my graduate studies. I was greatly aided in making this study by many scholars who freely gave their advice and valuable assistance. Dr. Richard H. Shryock of theHistory Department of the University of Pennsylvania, with whom the work was done, contributed encouragement, suggestions and construc­ tive criticism to the undertaking in all stages, and he many tlmes assisted in clarification of thought and crystallizationof ideas throughhis careful discussion of the problems involved. For helpful suggestions I am under obligation to Dr. W. B. McDaniel, 2nd, Librariarlof theCollege of Physicians of Philadelphia, Dr. Henry E. Guerlac, Professor of theHistory of Science, Cornell University\ Dr. George Rosen, Editor of the 1ournal of the Histo�y of Medlcine and Allied Sciences, Dr. ErwinH. Ackerknecht, Professor of the History of Medicine, i University of Wisconsin, Dr. Henry E. Sigerist, formerly Director of the Institute of the History of Medicine, 1ohns Hopkins University, Dr. Geddes Smith of the Commonwealth Fund, and Dr. Russell Francis of the University of Pennsylvania. Dr. W. C. McDermott of the Classics Department of the University of Pennsylvania has been most helpful in interpretingthe work of Marcus Antonius Plenciz. Dr. Evan C. Horning and Dr. Claude Deischer of the Chemistry Department aided withthe chemical terms. Mr. Samuel Hopkins Adams !JfAuburn, N. Y. has kindlydirected the author to useful materials. The work could not have been completed without the use of certain ill excellent libraries and the courtesy extended by theirlibrarians, notably theLibrary of the College of Physicians of Philadelphia, theArmy Medical Library in Washington andCleveland, the Main andMedical Libraries of the University of Pennsylvania, the Library of Cornell University, and the Rush Rhees, Women's College and Medical Libraries of the University of Rochester. ' Phyllis Allen Pblladelphla May 24, 1949 1. Chapter 1. IntroductoryNote At the opening of the nineteenth century, modern medicine had progressed so steadily that solutions to outstanding problenis seemed just around the corner. Inthe three centuries following the initialwork of Vesalius, anatomy had become a science. The human bodywas ex­ plored as effectively as was the terrestrial globe in the same era. In gross anatomy discovery after discoverywas made, and many landmarks bear the names of those who first located them: Gllsson's c1,tpsule, the antrum of Highmore, the circle of Willis, Peyer's glands, and others. No longer did medicine rely uponthe antiquated lore of Galen - medical men observed for themselyes. Physiology also profited from the develop­ ment of anatomy, while ;l'enewed interest in clinical medicine led to a return to the principle�· of Hippocrates. By the end of the eighteenth century, there was a much better understanding of the composition and functioning of the human body than had ever existed before. This understanding was further advanced by progress in the new field of pathologic anatomy. Less than twen.ty-five years after the publi­ cation of Morgagni's classic work on pathologic anatomy in 1761, French physicians took up this work and added to it. The ravages of disease were not only described as they affected the various organs of the body, but the lesions were correlated with clinical symptoms so as to give a clear picture of the disease under observation. Where heretofore diagnosis of a disease had been dependent almost solely upon the ob- 2. servation of obvio� symptoms, now the physicians were able to dif­ ferentiate among various disorders - with the knowledge that certain symptoms were characteristic of one disease and not of another. Accurate clinical observation became doubly important. Charac­ t�ristic signs and syndromes were added to thediagnostician's reper­ toire. The development and improvement of aids to the senses, �d of measuring devices, became extremely importantin diagnosis. Th� stethoscope, percussion, the use of the watch and thethermometer, to name a few, all aided the physician. Clinical stailstics, as applied by P. -C. -A. Louis to prove thedanger of venesection, also played a part. Mortality statistics � been compiled as early as 1662, but it took some time to put themon a sailsfactory basis. Such statistics were an im- , portant feature of Jacques Rene, Tenon's expose of thehospitals of Paris in 1'18'1. The nosologists of the eighteenth century had worked out an elaborate systemization of disease based on symptoms. Each symptom was considered a disease in itself. Needless to say, this made a tremen­ dous list Other systematizers such as Wllllam Cullen, were more moderate; but their classifications were, of necessitf, based largely on classes of symptoms because there was no other satisfactory basis available at the_ time. After the work of the pathologic anatomists, how­ ever, the classification of disease could be based on a correlation of symptoms with the lesions found at autopsies. This resulted in a new concept of specificity and a different set of specific diseases. it involved 3. the taskof breaking down such a concept as ''bilious fever" into malaria, typhus, typhoid and yellow fevers. Diseases of thechest were no longer a unity, but, according to the interrelation of symp­ toms and tissue changes, now became phthisis, pneumonia. pleurisy, andso on. In some instances, three or four entities emerged where only one had be�n suspected previously. These developments raised a new problem. If three or four diseases were now recognized where formerly there had been only one, to what must be ascribed the differences between them? Could lt be thatthere were an equal number of factors in theexternal and in­ ternal (body) environments, which were responsible for thedifferen­ tiation? By the last years of the eighteenth century, physicians had begun to ask these questions seriously. Some writers, in suggesting answers, attempted to make distinctions among the external factors (remote causes such as miasmata), which they believed to be involved in disease, but there was little material evidence available to substan­ tiate their conclusions. The classification of diseases into more definite entities, and the subsequent attempt to account .for differences between them, proved of great interest to Americans. As early as the.-1790's there was al- ready considerable discussion of the specif�c· causes of distinct diseases. Although this discussion was made P?ssible, in the long run, by the de­ velopments in disease identification mentioned, a· more immediatemo­ '• tivation was supplied � America by the old controversy over contagion. Whatever the ultiJJlate causal factors might be in such epidemic diseases as were already fairly well-recognized (as yellow fever), how could one account for theirrapid spread? Were they transmitted by humancon­ tacts? Suchquestions could also be asked about vaguely defined con­ cepts (such as ''bilious remittent fe:vers") even before the diseases now known to have been involved were identified. Later, thesharper differentiations already mentioned would become more specWc and mean1ngfal. Another factor creating interest in etiology was the prevalence of great epidemics, notably plague in the seventeenth century, smallpox in the eighteenth, and cholera in the nineteenth. In order to free mankind from