22 BACTERIA. 



is a small drum-stick shaped bacillus, similar to the putre- 

 factive bacillus described by Bienstock, which, on making 

 its way into a surgical wound, sets up a series of changes in 

 the tissues, accompanied by the production of a most 

 virulent poison, which, acting apparently on the nervous 

 system, gives rise to reflex spasms and convulsions, and 

 a ■ condition known as lock-jaw or tetanus is set up. 

 This organism is found on the manure heap, in cultivated 

 soil, and even in water that comes from such soil ; it is also 

 found in the dust of hay, straw, and even in the harness and 

 cloths used for equipping the horse. If water containing 

 these organisms be used for the purpose of washing a con- 

 tused wound, or if any of the above dirt or dust should obtain 

 access to such a wound — -often merely a most insignificant 

 bruise — tetanus or lock-jaw is set up with terrible certainty, 

 and the patient very frequently succumbs to the disease. 



Innumerable other instances might be given in proof of 

 the statement that the knowledge, first, of the forms, and, 

 secondly, of the biological and physiological characteristics 

 of the various micro-organisms, is now absolutely necessary 

 for a thorough understanding of even many everyday pro- 

 cesses. The colour formed in " blue milk " is due to the action 

 of a micro-organism ; as also are the phenomena of bleeding 

 bread, the Cape meal orange ferment, and the characteristic 

 appearance of green cheese. As a result of the knowledge 

 gained through the study of the life history of septic 

 organisms, thousands of valuable lives have been saved in 

 our surgical wards alone ; large industries have, through 

 Pasteur's indefatigable exertions, been preserved from almost 

 absolute ruin ; as a result of the observations of numerous 

 investigators, our knowledge of certain classes of diseases is 

 gradually becoming more precise and accurate, and the 

 time has now arrived when we may look forward to a 

 system of medicine in which, by preventive and curative 

 inoculation, we shall be able to grapple successfully with 

 some of the deadliest forms of disease with which we have 

 at present helplessly and almost hopelessly to contend. 



Literature. 



The following works may be consulted : 

 Bienstock. — Zeitschr. f. Klin. Med. Bd. viii. p. i, 1884. 

 CoHN. — Beitr. z. Biologic der Pflanzen, Bd. 11., 1876. 



