152 RELATIONS OF BACTERIA TO DISEASE. 



spending skin eruptions may be produced by poisoning 

 with certain drugs. In the nervous system degenerative 

 changes have been found in diphtheria, both in the spinal 

 cord and in the peripheral nerves, and have been re- 

 produced experimentally by the products of the diphtheria 

 bacilli. There is also experimental evidence that the 

 bacillus coli communis and the streptococcus pyogenes 

 may, by means of their products, produce areas of softening 

 in the spinal cord, and this may furnish an explanation of 

 some of the lesions found clinically. It is also possible 

 that some serous inflammations may be produced in the 

 same way. General malnutrition and cachexia are, of 

 course, of common occurrence, and it is a striking fact 

 found by experiment that after injection of bacterial 

 products, e.g., of the diphtheria bacillus, a marked loss 

 of body weight often occurs which may be progressive, and 

 ultimately lead to the death of the animal. 



Symptoms. Many of the symptoms occurring in 

 bacterial affections are produced by the histological changes 

 mentioned, as can be readily understood ; whilst in the 

 case of others, corresponding changes have not yet been 

 discovered. Of the latter, fever, with its disturbances of 

 metabolism and manifold affections of the various systems, 

 is the most important. The nervous system is especially 

 liable to be affected convulsions, spasms, coma, paralysis, 

 etc. being common. The secretory function of the glands 

 of the alimentary canal, of the salivary glands, may be dis- 

 turbed or practically stopped, a striking analogy to what 

 is found in the action of various drugs. 



These tissue changes and symptoms are given only as 

 illustrative examples, and the list might easily be greatly 

 amplified. The important fact, however, is that nearly all, 

 if not quite a//, the changes found throughout the organs 

 (without the actual presence of bacteria), and also the 

 symptoms occurring in infective diseases, can either be experi- 

 mentally reproduced by the injection of bacterial poiso?is or 

 have an analogy in the action of drugs. 



