430 



Dr. C. Bolton. On the 



[Jan. 25, 



•0*5 c.c. of the washings is added to 2 c.c. serum, so as to eliminate any 

 possibility of a precipitate of albumin being thrown down from the fluid, in 

 which the granules are suspended, by the immune serum. 



The tubes are incubated for four or five hours and then examined by the 

 naked eye and also microscopically. 



Agglutination. — A very fine deposit consisting of agglutinated granules is 

 seen, sometimes only with a lens, at the bottom of the tubes up to a certain 

 •dilution which varies according to the strength of the serum. The super- 

 natant fluid contains granules in all stages of agglutination, and if the tubes 

 .are allowed to stand in the ice chamber till the next day, all the agglutinated 

 granules are found to have settled to the bottom. 



The reading of the tubes is taken at the end of four or five hours' incuba- 

 tion, and controlled by that taken on the following day, both macro- and 

 microscopically. The reason for taking the reading twice is because 

 bacteria are liable to be found in the fluid at the end of 24 hours, since 

 the scraped mucous membrane cannot be sterilised by heat. 



The saline control shows no such deposit or agglutination, and the control 

 containing the washings shows no precipitate or deposit. The blood of a 

 normal rabbit shows no deposit and no agglutination, and can therefore be 

 used as a control. 



The amount of deposit is just sufficient to be accounted for by the sub- 

 sidence of the granules, and on shaking it up the agglutinated granules pass 

 into suspension, forming a delicate precipitate. Vigorous shaking disentangles 

 the granules, and the appearance of the solution becomes the same as it was 

 when the granules were first added. 



It is thus evident that the serum possesses an action upon the granules 

 themselves, and that this action is similar to that of the bacterial 

 agglutinins. The agglutinin appears in the rabbit's blood in small amounts 

 about 14 days after the first injection, and can be quite easily recognised 

 after a second injection. 



Effects of Heat. — After exposure to a temperature of 58° to 60° for half 

 an hour the serum agglutinates gastric granules in as high a dilution as it 

 •does when unheated. In this property of resisting heat the agglutinin 

 resembles those of bacterial origin. 



3. Action wpon the Soluble Proteids of the Gastric Cells. 



Method. — The solution of proteid is prepared by grinding up the mucous 

 membrane of the guinea-pig's stomach, previously washed free from blood, 

 .as described above, in a glass mortar with normal salt solution. 



The emulsion is centrifugalised in order to get rid of most of the solid 



