THE METHODS of BACTERIOLOGICAL INVESTIGATION. - 1886 - AUTHORS PREFACE. - URGED by the wish of my highly esteemed teacher, the Geheimrath Koch, I have attempted in the following work to meet the lack of a comprehensive representation of the met hods of bacteria-investigation. It was my endeavor, as an historical and experimental critic, to sift the whole of the literature, which was extraordinarily scattered and in part very difficult of access, and to select the good from the hardly conceivable confusion of useful and use1 ess communications, in order to give to the independent investigator a useful hand-book, and to the beginner a trnstworthy introduction into this territory - TRANSLATORS PREFACE - THIS translation of Hueppes excellent work on the Methods of Bacteriological In estigat ion w as suggested by the want in English of a satisfactory text-book on this subject for the use of students working under my direction in the Carnegie Laboratory. The preparation of the original was undertaken by Dr. Hueppe, at the request of Prof. Robert Koch, and the work has been thoroughly and care fully done. It shows a complete familiarity with the subject in hand, is comprehensive in character, and treats carefully aUpf the approved methods of investigation. Some difficulties have been met in the transla tion which those acquainted with this kind of work mill readily understand. It is literal so far as is consistent with clearness, and no attempt has been made to attain elegance in style or diction but it is well known that many German terms have no exact English equivalent, and can only be rendered accurately by a roundabout expression. This is well illustrated by 31assenkultur as translab edby quantity-culture on page 101 et seq., which means a culture, whether pure or not, where zt great quantity or bulk of bacteria are growing but, since this expression can not be inserted each time in the text, quantity-cuZtu e w ill be used wherever it occurs. The labor of prepamring the translation was performed in the short intervals of leisure found in the midst of numerous other duties, and was unavoidably interrupted just before its completion, so that some errors may be found in the book, but I think that none of serious importance have escaped correction. The author has requested me to emphasize the fact that the short, concise form chosen in the work is based on an extensive historical and ex perimentztl review of the whole subject, and that if any methods, still much used, have been omitted or only briefly considered, it is because they have not now the significance or importance that has been ascribed to them by other rriters. I here desire to aclmowledge my indebtedness to Dr. L. TV. IIubbard and Dr. S. N. Nelson, both of New York, for valuable assistance kindly ren dered me in the translation. The morlr has been very favornbly received in Germany, and if this translation meets only a smn, ll part of the same consideration in America, I shall feel well repaid for the labor expended. CARXEGI L E A BORATOR hT Y s, m Y o a, December l, 1885. CONTENTS. PAGl INTRODUO . T IO . N . . . . . . . . 9 True Saprophytic Forms . . . . . . . 11 1. SPOXTANEOUGBE XERATIO A N N D TIKE PRINOIPL O E F B S TERIL IZATION . . . . 0 . . . g 16 11. FORM O B F BA TERI A A N D MIOROSOOPIO T A E L C HNIQUE . . 28 A. The True Endospore Bacteria . . . . ...