ee IOWA ACADEMY OF SCIENCES. 



BACTERIA, THEIR RELATION TO MODERN MEDICINE, THE ARTS 

 AND INDUSTRIES. 



BY L. H. PAMMEL. 



It has been customary for the president, in making his retiring address, to 

 choose some popular subject and discuss it on broad lines. In some cases my 

 predecessors have given a resume of the scientific literature in our own State, and 

 I need not say that we all feel proud of the work accomplished by this small band 

 of workers. I shall venture, in this address, to discuss the subject of Bacteria 

 along general lines and hope I may be able to correct some popular misapprehen- 

 sions concerning the subject. 



The word Bacteria has almost become synonymous in the minds of some with 

 certain diseases in lower animals and man, but this popular construction is so 

 erroneous, that I propose in this address to show the extent and importance of the 

 question of bacteriology to many important problems. 



We shall treat this question in the following way: History, methods of study, 

 structure, question of species, hygienic problems, Bacteria and their relation to 

 economic problems in agriculture and other industries. 



We are told in an admirable treatise by Loeffler- on the historical development 

 of bacteria that the presbyter, Kircher more than 235 j^ears ago observed that air, 

 water, soil, cheese and putrefactive substances contained countless numbers of 

 " worms " as he designated them. Having observed these living organisms he at 

 once concluded that the Italian plague of 1656 could be traced to these " worms;" 

 but, the most remarkable of the early workers was Antony von Leeuwenhoek a 

 mechanic of Delft, Holland, who had learned the art of making lenses while an 

 apprentice in a linen factory. With his simple lenses and excellent powers of 

 observation he was enabled to observe Bacteria of putrid material, tartar of teeth, 

 etc. Some of the forms were figured and described. He says": " Mit grosser 

 Bewunderung sah ich, dass uberall in den genannten Material viele sehr winzige 

 Thierchen enthalten waren, welche sich auf die ergoetzlichste Weise bewegten." 

 From his figures and descriptions one cannot doubt but that he was dealing with 

 bacteria. We cannot here give in detail the conclusions reached by Vallisneri, 

 Goiffon, Nicholas Andry and Varro, but they concluded that these organisms caused 

 disease. The celebrated Linnaeus^ could not dispel from his mind that certain 

 living organisms caused disease. The learned Viennese physician, Marcus Antonius 

 Plenciz, discussed in a clear and logical way the cause of contagious diseases. He 



iVorlesungen ueber die geschichtliche entwickelung der Lehre von den Bacterien 

 fur Aerzte und Studirende, Erster Theil bis zum Jahre IS7S, 37 figures and 3 plates pp 

 252, Leipzig, F. C. W. Vogel, 1887. 



2LoeHier 1. c. p. 5. 



SLoefBer 1. c. p. 6. 



