1915] Frederic G. Goodridge and Max Kahn 121 



sulfur excretion (0.88 gm. per day) occurred in a series of 13 cases 

 of Carcinoma. The same series also showed the lowest average neu- 

 tral-sulfur excretion (not by the Salomon and Saxl method) — 0.20 

 gm. per day. The proportion of neutral sulfur to total sulfur in the 

 series was considerably higher than the normal proportion. They 

 conclude, however, that " it is a precarious undertaking to diagnose a 

 malignant tumor on the basis of the absolute or relative amount of 

 neutral sulfur in the urine." 



Experimental. The following methods were used by us for 

 determinations of the colloidal nitrogen and the neutral sulfur in the 

 urine. 



CoLLOiDAL-NiTROGEN. The urine was first tested for coag- 

 ulable protein, which, if found, was removed by means of heat 

 coagulation, with addition to the boiling liquid of a few drops of 

 dilute acetic acid sol. To 100 cc. of mixed, filtered, 24-hr. specimen 

 of urine, zinc sulfate was added in sufficient quantity to effect Satu- 

 ration. The saturated liquid was allowed to stand for 24 hours, 

 then was filtered through ashless paper, and the precipitate washed 

 several times on the paper with saturated zinc sulfate Solution, to 

 remove nitrogenous substances adherent to the precipitate. The 

 paper and precipitate were then placed in a Kjeldahl flask and the 

 nitrogen content determined by the Kjeldahl method. The total 

 nitrogen in 5 cc. of urine was also determined by the Kjeldahl 

 method. The ratio of the nitrogen in the zinc sulfate precipitate to 

 the total urinary nitrogen was computed. 



Neutral-sulfur. The technic of the Salomon and Saxl neu- 

 tral-sulfur test is the following: 150 cc. of urine, freed from coag- 

 ulable protein by heat and acid, are diltited with 100 cc. of water. A 

 mixture of 100 cc. of sat. aqueous sol. of barium hydroxid and 50 

 cc. of sat. aqueous sol. of barium chlorid is added, the liquid filtered 

 and the filtrate tested with barium to see if precipitation is complete. 

 In Order to remove the ethereal sulfates, 300 cc. of the filtrate are 

 treated with 30 cc. of conc. hydrochloric acid sol., and boiled for 

 15 min. in an Erlenmeyer flask, using a funnel condenser. The 

 flask is then placed on a water-bath for 24 hr. Of the clear filtrate, 

 200 cc. are mixed with 3 cc. of hydrogen peroxide (perhydrol- 

 Merck), and boiled for 15 min. with a funnel condenser. After 

 boiling, the liquid is transferred to a conical graduate, whcre, at the 



