SKETCH OF DR. MAX VON PETTENKOFER. 843 



to its outbreak in concrete cases, which may be designated as local, 

 temporal, and that of the individual disposition. What we call the 

 locality must have the infectious matter concealed within itself before 

 persons abiding there are affected. Not every time is alike favorable 

 to the infection ; and, when place and time concur, only those persons 

 are affected who offer a suitable personal disposition to the poison. 

 Such persons, even in the worst cases, form hardly five per cent of 

 the population. Thus, the spread of cholera is found to be governed 

 by three factors, the operation of which can be comprehended by all. 

 Further, Dr. Pettenkofer has taught that the danger of attack with 

 cholera does not ordinarily come from persons who are sick, but pri- 

 marily from the place, showing that the physicians are no more liable 

 than others, and greatly relieving the duty of caring for the sick of its 

 most formidable terrors. The rules respecting disinfection, the dis- 

 covery of a term, not longer than fourteen days, to which the preva- 

 lence of cholera in a particular house is limited, and the prescription 

 of the measures which every one should adopt in the matters of food 

 and drink, clothing and cleanliness, are points of great value for the 

 saving of lives, in which, says Dr. Stieler, Dr. Pettenkof er's determina- 

 tions have been most definite. If any one makes the objection that 

 these rules contain nothing particularly new, the answer is returned 

 that modern medicine no longer deals in mysterious receipts, but is 

 associated with the nearest and most diversified elements in our life, 

 which not every one knows how to satisfy, or which are neglected 

 because they are commonplace, every-day affairs. It appears now to 

 be the chief purpose of hygiene to convince the masses that the com- 

 monest matters are the most important. No science can be less aris- 

 tocratic, none has to be more intent on popularizing its results. In 

 this popular spirit Dr. Pettenkofer prepared his treatises on " What 

 we can do against the Cholera," and " The Present Condition of the 

 Question of the Cholera." He was president of a cholera commis- 

 sion which met in Berlin at his suggestion, and was a member of 

 the congress which met at Weimar in 1867, with similar objects. 

 His investigations on the cholera, which were afterward extended to 

 typhus and to the various sources of disease in the ground, the air, and 

 the water, have given the impulse to the most comprehensive 

 researches by hosts of inquirers. He constructed an apparatus for 

 exact investigations in respiration, and undertook, in connection with 

 Voit, a series of comprehensive labors on the respiration and nourish- 

 ment of men and animals, through which many data were collected 

 having an important bearing on the theory of metamorphoses of 

 matter. 



Dr. Pettenkofer's works have been published for the most part in 

 professional journals. Since 1842 he has contributed numerous articles 

 in chemistry and kindred subjects to " Biichner's Repertorium," " Ding- 

 er's Journal," and the " Denkschrift " of the Munich Academy of Sci- 



