TRANSACTIONS OF SECTION I. 809 



-with the water. About 1'5 c.c. of this mixture was drawn into the injecting 

 cannula. The cannula consisted of a piece of glass tubiug drawn to a sharp 

 point, with a lateral opening a short distance behind the point. This opening was 

 made of a size just sutticieut to allow the dust to pass easily through. No force 

 was needed in the injection, the negative pressure due to the inspiratory act being 

 sutKcient to suck the moisture into the cavity. 



The effects due to the simple dust were observed in several animals of both 

 kinds. These consisted in hyper.iemia of the lung with exudation of fluid and red 

 cells into the alveolar spaces. There was also exudation of fluid into the pleural 

 cavity in several instances, and it contained usually a considerable number of red 

 cells also. To some extent the epithelium covering, the pleural surface of the lung, 

 was thrown oft' into the fluid. 



The dust was rapidly absorbed into the lymphatic vessels, and could be seen, 

 even after twelve hours, as small round yellowish patches in the pleural membrane. 

 These when examined microscopically were found to contain large numbers of 

 glass particles. 



The injection of the bacillus pyocyaneus followed after a time, varying from one 

 to twenty-six days. 



In the following table we have a summary of the observations. 



Guinea-pigs. — Six animals, with controls: — 

 Two recovered completely. 

 Three survived the control animals for a period. 

 One was a contradictory instance, for this died sooner than the control 



animal. 

 Rabbits — Seven animals, with controls: — 



Two recovered, the controls dying on the second day after infection. 

 Three survived the controls in two cases one day, and in one case 



eight days. 

 Two cases in which the bacillus was injected into the opposite pleural 



cavity. One died with the control, the other earlier. 



The conclusion which is derived from these experiments is that the early stages 

 cf inflammation confer a certain amount of immunity on the pleural cavity in 

 which the inflammation has been set up. It does not seem to vary in its protective 

 power during the tirst month or so after the inflammation has been set up. In 

 those instances where there was not complete recovery it was usually found that 

 bacilli occurred to a much greater extent in the pleural exudation of the control 

 animals than in that of those infected with glass dust. 



The death of the last two rabbits points to the fact that probably the protection 

 conferred is strictly localised in the inflamed tissues. 



On the Changes in Nerve Cells due to Functional Activity. 

 By GusTAv Mann, M.D. 



6. On the Effect of Gravity on the Circulation. By Dr. L. Hill. 



7. Experimental Inquiry upon the Different Tracts of the Central Nervous 

 System. By F, W. Nutt, M.D. 



The origin and termination of the fibres of the fillet were investigated by noting 

 the degeneration resulting from unilateral separation of the nuclei of Goll and 

 Burdach from the arciform fibres issuing therefrom. The degenerated arciform 

 fibres were traced by Marchi's method into the opposite interolivary layer, and 

 thence into the fillet. The degenerated fibres of the fillet were followed most 



