448 



CHAPTER XXII. 



General Diseases. 



general remarks simple fever stable fever — malarial 



fever surra tsetse fly disease influenza contagious 



pleuro-pneumonia strangles anthrax south african 



horse sickness port pirie horse disease cerebro-spinal 



fever glanders and farcy epizootic lymphangitis 



ulcerative lymphangitis weed tuberculosis dourine 



horse-pox diabetes mellitus diabetes insipidus purpura 



hemorrhagica hiemoglobinuria rheumatism rabies 



tetanus blood-poisoning navel-string infection. 



General Remarks. 



We may safely conclude that all the general diseases which are 

 of an infective nature, are caused by the entrance into the system 

 of minute vegetable or animal organisms. As a rule, the former 

 are bacteria (pp. 19 and 63); and the latter, parasites which live 

 in the blood (haematozoa). The specific parts played by different 

 kinds of bacteria are of great variety. Some bacteria produce 

 colour, as, for instance, a blue tinge in milk; others, light, as 

 we may see by the phosphorescence produced by the photo- 

 hacterium phosphorescens during the fermentation of sugar, under 

 certain conditions. They are the causes of fermentation and putre- 

 faction, and, in many cases, of disease. Various kinds of fermenta- 

 tion-producing bacteria are essential to the proper performance 

 of digestion. In plant life, bacteria are the means by which 

 lucerne and many other vegetables absorb nitrogen from the 

 air. Dr. Patrick Manson (Gibson's '' Text-book of Medicine ") 

 tells us that " disease-producing organisms elaborate poisonous 

 substances, which call forth certain symptoms, of which some are 

 specific, and belong exclusively to a particular -species, while others 

 are general, and shared by many organisms. Poisonous sub- 

 stance obtained from a tetanus culture, for instance, which, when 

 injected into an animal, produces tetanus, is a specific poison ; 



