33 



The above data show that the injected material was ex- 

 creted in the urine in considerable amounts. While it did 

 not yield the heat-precipitation test in the urine, it did give a 

 strong reaction in an aqueous solution of the (NH 4 ) 2 SO 4 pre- 

 cipitate from the urine. 



Of course it is to be noted that in the case of the plain urine, 

 we have much less of the injected material corresponding 

 to the Bence Jones body than is present in cases of "mye- 

 lopathic albumosuria," and the fact has been commented upon 

 by Coriat, Hutchison, Rosin, Simon, Sussman, Matthes, 

 Rostoski, Ribbinik, Huppert and Magnus-Levy, that in their 

 cases, although the precipitate was obtained in the urine 

 at low temperature, it did not completely dissolve on further 

 heating. The disappearance of the precipitate after con- 

 tinued heating is not always noted even when the Bence Jones 

 protein is present, as the above-named observers showed, and 

 this reaction is not a true test for the Bence Jones protein. 

 We must bear in mind that the influence of salts has a great 

 deal to do with the solution and precipitation of this protein 

 as is the case with other proteins. This fact has been demon- 

 strated by Spiro, 1 Pauli and Rona 2 and Hammarsten. 3 



In order to clear up the obscure points relating to the pro- 

 tein excreted in this experiment, the aqueous solution of the 

 precipitates obtained from the urine by treatment with 

 (NH 4 ) 2 SO 4 was dialyzed till free from sulphate and speedily 

 evaporated over a water bath until the liquid had a syrupy 

 consistency. The following experiment was undertaken to 

 find out what reactions occur on heating a sample of urine 

 (sp. gr. 10.20) containing an amount of the substance approxi- 

 mately equal to the proportion in which it exists in cases 

 of myelopathic proteosuria. When the syrupy solution of 

 the excreted substance was added to the urine in varying 

 proportions, no change in the urine took place on heating. 

 The treated urine gave marked precipitates with picric acid and 

 trichloracetic acid, however. These reactions did not take 



1 Spiro: Zt. phys. Ch., 1900, xxx, p. 182. 



2 Pauli and Rona: Beit. f. ch. Phys. und Path., 1902, ii, p. i. 



3 Hammarsten: Pfliiger's Arch. f. d. ges. Phys., 1878, xxviii, p. 65. 



