NUCLEOALBUMINS. 751 



If the acid filtrate is treated with seralbumin, a new and similar precipitate 

 is obtained, due to the presence of a residue of the substance which pre- 

 cipitates proteids. The most important of these proteid-precipitating 

 substances is chrondroitin-sulphuric acid and nucleic acid, although the 

 latter appears to a much smaller extent. Taurocholic acid may in a few 

 instances, especially in icteric urines, be precipitated. The substances 

 isolated by different investigators from urine by the addition of acetic 

 acid and called " dissolved mucin " or " nucleoalbumin " are considered 

 by MORNER to be a combination of proteid chiefly with chrondroitin- 

 sulphuric acid, and to a less extent with nucleic acid, and also perhaps 

 with taurocholic acid. 



As normal urine habitually contains an excess of substances capable 

 of precipitating proteids, it is apparent that an increased elimination of 

 so-called nucleoalbumin may be caused simply by an augmented excretion 

 of proteid. This happens to a still greater extent in cases where the 

 proteid as well as the proteid-precipitating substance is eliminated to an 

 increased extent. 



Detection of so-called Nucleoalbumins. When a urine becomes cloudy 

 or precipitates on the addition of acetic acid, and when it gives a more 

 typical reaction with HELLER'S test after the dilution of the urine than 

 before, one is justified in making tests for mucin and nucleoalbumin. 

 As the salts of the urine interfere considerably with the precipitation 

 of these substances by acetic acid, they must first be removed by dialysis. 

 As large a quantity of urine as possible is dialyzed (with the addition of 

 chloroform) until the salts are removed. The acetic acid is added until 

 it contains 2 p. m., and the mixture allowed to stand. The precipitate 

 is dissolved in water by the aid of the smallest possible quantity of alkali 

 and precipitated again. In testing for chrondroitin-sulphuric acid a 

 part is warmed on the water-bath with about 5 per cent hydrochloric 

 acid. If positive results are obtained on testing for sulphuric acid and 

 reducing substance, then chondroproteid was present. If a reducing 

 substance can be detected but no sulphuric acid, then mucin is probably 

 there. If it does not contain any sulphuric acid or reducing substance, 

 a part of the precipitate is exposed to pepsin digestion and another part 

 used for the determination of any organic phosphorus. If positive results 

 are obtained from these tests, then nucleoalbumin and nucleoproteid 

 must be differentiated by special tests for nuclein bases. No positive 

 conclusion can be drawn except by using very large quantities of urine. 

 The filtrate from the nucleoalbumin can be used for the ordinary proteid 

 tests. 



Nucleohistone. In a case of pseudoleucsemia A. JOLLES found a phosphorized 

 protein substance which he considers as identical with nucleohistone. Histone is 

 claimed to have been found in some cases by KREHL and MATTHES, and by KOLISCH 

 and Bum AN. 1 



1 Jolles, Ber. d. deutsch. chem. Gesellsch., 30; Krehl and Matthes, Deutsch. Arch, 

 f . klin. Med., 54; Kolisch and Burian, Zeitschr. f. klin. Med., 2. 



