294 STRECKER'S RESEARCHES. [BOOK IL 



research on the bile was published in association with Gundlach in 

 the year 1847 and concerned the bile of the pig, in which they 

 discovered the sodium salt of an acid which they named hyocholic 

 acid and which we now term hyoglykocholic acid 1 . In 1848 Strecker 

 published in two parts his great research on the bile of the ox 2 ' 3 . 

 Starting from the cholic acid of Gmelin, Strecker succeeded, by 

 boiling this body with a solution of barium hydrate, in decomposing 

 it, obtaining as products of decomposition glycocoll and a non- 

 nitrogenous acid, obviously the same as that which Demarcay had 

 named cholic acid. Strecker called this acid cholalic acid, the name 

 by which it is now generally known, and assigned to it the formula 



Passing over his researches on the products of decomposition of 

 cholalic acid, we have to bring into special relief the second great 

 result of his research on ox bile. Having separated the glykocholic 

 acid which exists in that bile by precipitating it with neutral lead 

 acetate, he treated the nitrate with basic lead acetate, and obtained 

 a second precipitate containing the lead salt of an acid in whose 

 composition not only N but S entered; to this acid which (after 

 Lehmann) we now call taurocholic acid, Strecker applied the term 

 choleic acid (choleinsaure). 



Although unable to obtain taurocholic acid in a crystalline 

 condition, he succeeded, by the same method which he had employed 

 in the case of glykocholic acid, in decomposing it into taurine (which 

 Redtenbacher had already shewn to contain sulphur and to which he 

 had ascribed a correct empirical formula), and into cholalic acid. 

 Strecker had thus succeeded in shewing that the two bile acids, like 

 hippuric acid, are conjugate acids which readily split up into a non- 

 nitrogenous acid common to the two bile acids, and into amido- 

 compounds the N-containing glycocine on the one hand, and the 

 N- and S-containing taurine on the other. 



In a third great paper 4 Strecker recorded his researches on the 

 bile of various animals, investigating, inter alia, the mineral con- 

 stituents of the bile of fishes, and completing the research which he 

 had commenced with Gundlach on hyoglykocholic acid. 



Glykocholic acid, C 26 H 43 N0 6 . 



Glykocholic acid is the principal bile acid in the bile of man, the 

 ox and other herbivorous animals, and occurs in combination with 

 sodium. It is not found in the bile of carnivorous animals. 



1 Dr C. Gundlach und Dr Ad. Strecker, ' Untersuchung der Schweinegalle.' Annalen 

 d. Ghem. u. Pharm., Vol. LXII. (1847), pp. 205232. 



2 Ad. Strecker, ' Untersuchung der Ochsengalle.' Erste Abhandlung. Ann. d. Chem. 

 M. Pharm. , Vol. LXV. (1848), pp. 137. 



3 Ad. Strecker, 'Untersuchung der Ochsengalle.' Zweite Abhandlung. Annalen d. 

 Chem. u. Pharm., Vol. LXVII. (1848), pp. 160. 



4 Ad. Strecker, ' Beobachtungen iiber die Galle verschiedener Thiere.' Annal. d. 

 Chem. u. Pharm., Vol. LXX. (1849), pp. 149197. 



