A Simple Method of Diagnosing Pregnancy. 129 



A freshly passed specimen of urine from a pregnant woman is 

 tested for albumin by the biuret test. If the test be positive 15 c.c. 

 of urine are shaken with 0.3 gram of kaolin for 10 minutes on a 

 mechanical shaker, filtered and tested again ; the biuret test should 

 now be negative. If it be still positive the process must be re- 

 peated. 10 c.c. of the biuret-negative urine are then neutralized 

 with 1 per cent, acetic acid, or with 2 per cent, sodium carbonate 

 solution, 0.2 gram of dried placenta added, and the whole well 

 shaken. The shaking I find essential. 0.5 c.c. toluol is added to 

 restrict bacterial growth. The mixture is incubated for 12 hours, 

 filtered, and 5 c.c. tested by the biuret test. If negative the re- 

 maining 5 c.c. are left in contact with the substrate, incubated for 

 4 hours longer, and tested again. 



Controls of the urine of the pregnant woman without sub- 

 strate, of urine from a male with and without substrate, from a non- 

 pregnant female with and without substrate, and of the substrate 

 in 10 c.c. of distilled water, are set up and tested in the same way. 



The urine of the pregnant female in contact with the substrate 

 should give a positive biuret reaction: all the controls should 

 give negative reactions. The color of a positive test varies from 

 deep purple to lilac or rose in different cases. All blues and 

 greens are negative. 



Up to the present time 59 cases have been examined. Of 

 these, 12 urines tested before the above technique had been fully 

 developed, gave the following results: one male gave a negative 

 reaction both with the blood serum and the urine; of the 11 

 pregnant females, only 2 gave a positive reaction with the urine 

 although in every case the blood serum was positive. Since using 

 the kaolin method, and adopting the precautions mentioned in the 

 preceding paragraphs, the results have been very satisfactory. 



Urines from 47 Cases Examined. 



Pregnant females .... 



Males 



Non-pregnant females 

 Ectopic gestation .... 



29 — all positive. 

 6 — all negative. 



9 — 8 negative, I positive (fibroids of uterus). 

 3 — all positive. 



These positive results in pregnant females were gained in the 

 main from urines of cases estimated as from the 28th to 36th 



