THE ALBUMINOIDS. 71 
two of these substances, which he named Bemiglutin and hemicollin. 
Chittenden and Solley 1 distinguish between proto- and deuterogelatose, 
and true gelatin-peptone. Paal 2 has obtained similar substances by the 
use of hydrochloric, acid. By the use of Eaoult's method, he gives the 
molecular weight of gelatin as <S78 to 9G0, and of gelatin-peptone as 352. 
Strong reagents like sulphuric acid, on putrefaction, decompose 
gelatin with the formation of glycocine, 3 leucine, various fatty acids, 
glutaminic acid, carbon dioxide and ammonia. The absence of tyrosine 
should he noted. Schiitzenberger, 4 who has worked with gelatin by the 
same methods as he used with proteids, considers that gelatin, like 
proteid, is a compound of urea with certain amido-acids. 
The importance of gelatin as a proteid-sparing food, though it will 
m it replace proteid entirely in a diet, will lie considered under " Nutrition." 
Ohondrin is the name given to the impure gelatin obtained from 
cartilage (which see). 
Elastin. — Elastin is a material yielded by the yellow fibres of con- 
nective tissue. It offers great resistance to reagents, and may be pre- 
pared from the ligamentum nuchse by extracting the finely divided 
tissue successively with reagents in which it is insoluble, and in which 
adherent fatty, collagenous, and proteid matters dissolve (boiling water, 
1 per cent, potassium hydroxide, 5 per cent, hydrochloric acid, alcohol 
and ether). By this means a substance free from sulphur is obtained. 
Chittenden and Hart, 5 in some of their preparations, omitted the 
extraction with potash, and in these a small percentage of sulphur (0*3) 
was obtained ; this may be due to proteid impurities, or it may be loosely 
combined in the elastin molecule. Schwartz 6 has also prepared a sulphur- 
containing elastin from the aorta. 
The following table shows the results of elementary analyses in per- 
centages :— 
MiillerJ Tilanus.8 
Horbaczewski.'- 1 
Chittenden 
and Hart. 
Schwartz. 
c . 
H . 
N . 
. 
s . 
55-09-55-7 
7-11-7-67 
15-71-16-52 
20-7-21-15 
54-9-55-65 
7-25-7-41 
17-52-17-74 
19-5-20-33 
54-32 
6-99 
16-75 
21-94 
54-24 
7-27 
16-7 
21 -69 
0-3 
53-95 
7-03 
16-67 
21-97 
0-3S 
Derivatives of elastin. — Elastin is gradually and slowly dissolved by 
1 Journ. Physiol., Cambridge and London, vol. xii. p. 25. 
2 Ber. d. deutsch. chem. Gesellsch., Berlin, Bd. xxv. 
3 On the preparation and estimation of glycocine from gelatin, see C. S. Fischer, ZfscJn-. 
f. jrfiysiol. Chem., Strassbnrg, Bd. xix. 8. 164 ; and Gonnennann, Arch. f. d. ges. 
Physiol., Bonn, Bd. lix. S. 42. 
4 Compt. rend. Acad. d. sc, Paris, tome cii. p. 1296. See also Buchner and Curtius, 
Ber. d. deutsch. chem. Gesellsch., Berlin, Bd. xix. S. 850. 
5 Ztschr. f. Biol., Miinchen, Bd. xxv. S. 368; Stud. Lab. Physiol. Chem., New Haven, 
vol. iii. p. 19. 
P Ztschr. f. physiol. Chem., Strassbnrg, Bd. xviii. 
7 Ztschr. f. rat. Med., Leipzig, Dritte Reihe, Bd. x. pt. 2. 
s < torup-Besanez, "Physiol. Chem.," Ann. 3, S. 148. 
9 Ztschr. f. physiol. Chem., Strassburg, Bd. vi. S. 330. 
