534 Dr. C. Bolton. [June 10, 



The gastrotoxic serum was in all cases obtained by injecting the washed 

 stomach cells of the guinea-pig into the rabbit, the blood serum of the rabbit 

 developing toxic properties for the guinea-pig's tissues. 



1. The Multiplicity of the Precipitins. 



My object was to ascertain whether the same precipitin or different precipi- 

 tins were concerned in the precipitation of the various proteids. 



Method. — The proteid solutions examined were albuminous extracts of the 

 gastric, hepatic, and intestinal cells, and the blood serum of the guinea-pig. 

 The extracts were made by grinding up the cells to a pulp, shaking up the 

 latter with salt solution, and filtering through a Berkefeld filter. The proteid 

 solutions were all made of such a strength that a faint cloud was formed on 

 testing them with potassium ferrocyanide and acetic acid. It is necessary to 

 use the solutions of the same strengths, because the precipitate is soluble 

 in excess of the precipitable substance, and therefore if albuminous fluids of 

 different strengths are employed, erroneous results will follow. 



If equal volumes of such a proteid solution and anti-serum be mixed 

 together and incubated for four hours, and if the precipitate which forms in 

 the solution be removed by centrifugalisation, the resulting solution, which 

 will consist of a two-fold dilution of anti-serum, will be found to be 

 incapable of precipitating any further the proteid solution. In this way one 

 can easily remove the precipitin for any particular proteid, and the solution 

 can then be tested with regard to its power of precipitating a different 

 proteid. In all cases, of course, a control must be prepared, so as to prove 

 that the precipitin has been actually removed. 



In this way the precipitins for each of the four proteid solutions mentioned 

 above were removed, and the resulting serum diluted to different degrees and 

 tested as to its capacity of precipitating the three remaining proteids, with the 

 following results : — 



Removal of the Precipitin for Stomach-cell Proteid. — A solution of gastro- 

 toxin from which the precipitin for stomach-cell proteid has been removed 

 is thereby rendered quite incapable of precipitating the proteids of liver cells, 

 intestine cells, or blood serum. 



Removal of the Precipitin for Liver-cell Proteid. — Removal of the precipitin 

 for liver-cell proteid slightly weakens the power of the gastrotoxin to preci- 

 pitate the proteids of stomach cells and blood serum, and it completely 

 deprives it of the power of precipitating intestine-cell proteid. 



Removal of the Precipitin for Intestine- cell Proteid. — Eemoval of this 

 precipitin renders the gastrotoxin incapable of precipitating liver-cell proteid, 



