93 MICRO-ORGANISMS AND DISEASE. [CHAP. 



liver (chiefly coagulative necrosis of tracts of the liver tissue), 

 and inflammation of the lungs. 



Inoculations of suitable sterilised nourishing fluids made 

 from the spleen, liver, and lung of such animals always result 

 in producing a copious crop of the characteristic bacilli, as do 

 those made with the lung and bronchial glands of pigs dead 

 of swine plague ; but from the blood of the pig the cultiva- 

 tions do not as a rule succeed, nor as a rule from the blood of 

 mice ; occasionally, however, those from the blood of rabbits 

 dead of the disease do succeed. 



Quite recently I have ascertained that pigs inoculated with 

 artificial cultures of these rods (started from the pig, mouse, 

 or rabbit dead of the plague) or with the diseased organs of a 

 mouse or rabbit, suffer from a mild form of the disease, which 

 after one or two weeks passes off completely. I have had pigs 

 that had been twice inoculated, the first time with artificial 

 cultures, the second time with diseased organs of mouse and 

 rabbit, and each time the pigs suffered from a mild form of 

 the disease. They were then inoculated a third time with the 

 juice of the diseased (fresh) ?^ng of a pig dead of the plague ;. 

 this time also they showed distinct symptoms of the disease, 

 but after a few days to a week they completely recovered. If 

 normal (or not previously inoculated) pigs are inoculated with 

 matter from the diseased fresh lung of a pig dead of the 

 plague, they as a rule die from a virulent form of the disease. 

 But in the above case they were protected by previous in- 

 oculations, not altogether against a new attack but against a 

 fatal attack. 



(i) Bacillus Leprcc. Armauer Hansen J first ascertained the 

 existence of large numbers of minute bacilli in the peculiar 

 large leprosy-cells of Virchow, which occur in the nodules of 

 leprous patients. Neisser confirmed this, and considerably 

 extended our knowledge of the bacilli, showing that they can 

 be readily stained pink with fuchsin or with Ehrlich's acid 

 solution of eosin-hsematoxylin. The bacilli are fine rods 

 about 0-004 to O'OOG mm. long and less than O'OOl mm. thick. 

 They are pointed at their ends, and always occur in masses 

 within the large leprosy-cells of the leprous tubercles of the 

 skin and internal organs. But they are also present in the 

 interstitial tissue of the nervous branches in the anaesthetic 

 variety of the disease. 2 Some bacilli are motile, others not ; 



1 Virchow' s Archiv, vol. Ixxix; and Quart. Jotirn. of Micro. Set. 1880. 

 y Compare also Coniil, Union Medicalc, IbSl, Nos. 178, 179, and Babes 

 Archives d. Plnjsi'.,logie, July, 1SS3. 



