166 APPLIED IMMUNOLOGY 



bility. The general opinion appears to be that while 

 it cannot be regarded as infallible in the diagnosis of 

 carcinoma, yet it has a distinct clinical value when 

 taken along with other tests and symptoms. 



Epiphanin Reaction 

 The epiphanin reaction of Weichardt is based on 

 practically the same principle as the meiostagmin re- 

 action, viz., an acceleration of diffusion in the fluid 

 when an antigen is brought in relation with the specific 

 antibody. SeifFert has shown that this phenomenon is 

 manifested by a change in reaction to phenolphthalein. 

 This test has been applied especially to the diagnosis 

 of syphilis. For this purpose 0.1 c.c. of a 1 : 10 dilu- 

 tion of the patient's serum is mixed with 0.1 c.c. of 

 alcoholic extract of syphilitic fetal liver, 1 c.c. of deci- 

 normal sulphuric acid and 1 c.c. of an exactly equiva- 

 lent solution of barium hydroxide are slowly added, 

 making a neutral mixture. On the addition of a drop 

 of an alcoholic solution of phenolphthalein, the fluid 

 turns red if the serum is syphilitic, but does not change 

 color if it is non-syphilitic. It is doubtful if this test 

 will become as widely used as the Wassermann reac- 

 tion for the diagnosis of syphilis. 



