1 84 LYMPH AND ALLIED FLUIDS. 
liquid of specific gravity about 1007-8, and of a faintly alkaline reaction 
It contains only about 1 per cent, of solids, chiefly inorganic salts, of 
which the greater part is sodium chloride, the other salts being potas- 
sium chloride, phosphates of lime and magnesia, and traces of iron and 
sulphates. 1 There is, as a rule, not more than 1 part per 1000 of 
proteids. These consist almost entirely of proteoses ; chiefly in the form 
of protoalbumose, which is precipitable by saturation with sodium 
chloride or magnesium sulphate. There is also a very small amount of 
serum globulin, but no scrum albumin or fibrinogen, nor is there any 
nucleo-proteid or fibrin ferment. Rarely peptone occurs. 
In addition to proteids and traces of nitrogenous extractives, there is 
present in cerebro-spinal fluid a non-nitrogenous substance peculiar to it, 
which has the property of reducing copper salts when heated with them 
in an alkaline solution. This was thought by Claude Bernard to be 
sugar. The substance, however, is not sugar, being non-fermentable, 
non-rotatory, and incapable of combining with phenylhydrazin to form 
a crystalline compound. According to Halliburton, it is pyrocatechin, 
and has the formula C 6 H 4 (OH) 2 , being probably one of the decomposi- 
tion products of proteids ; it occurs in traces in the urine. In tapped 
cases of hydrocephalus and meningocele the amount of this substance 
increases after the first tapping. 2 
The presence of proteoses, and occasionally of peptones, in the cerebro-spinal 
fluid, although these substances do not occur in blood or lymph, is of interest 
in connection with the theory of Gaskell, which supposes the central nervous 
system of vertebrates to have become developed in connection with a dorsal 
alimentary canal, such as is found in arthropods/ 5 No digestive ferment 
(pepsin, trypsin) has, however, been detected in cerebro-spinal fluid. 
Synovia differs from Lymph in containing a larger amount of solids 
and also a mucin-like substance. Mucin, according to Landwehr, 4 yields 
a reducing sugar on boiling with mineral acids, but, according to Ham- 
marsten, 5 this mucin-like substance of synovia does not yield such 
reducing sugar, and is of the nature of nucleo -albumin (containing 5 per 
cent, of phosphorus). 6 But the mucin-like material obtained by 
Salkowski 7 from synovia neither yielded phosphorus nor did it give 
any reducing sugar. 
Salkowski gives the following as the composition of the synovia 
analysed by him: — 
In 100 grins.— Water .... 93-084 
„ Mucin-like substance . . 0375 ( r i qq 
Other proteids . . . 4-824}°' iJ 
Fat . . . . -282 
„ Lecithin . . . . - 017 
Cholesterin . . . 0'569 8 
Inorganic salts . . . 0*849 (Nad 0772) 
1 Yvon, quoted by Halliburton. 
2 For further details consult Halliburton, " Cheni. Physiol.," p. 355; also "Keport 
of Spina Bifida Committee," Trans. Clin, Soc. London, vol. xviii. ; and jourrt. Physiol., 
Cambridge and London, vol. x. p. 232, where the previous literature will be found. 
3 Address to the Section of Physiology, Rep. Brit. Ass. Adv. Sc, London, 1896. 
4 Arch./, d. ges. Physiol., Bonn, Bd. xxxix. S. 193. 
5 Jahresb. il. d. Fortschr. d. Thier-Chem., "Wiesbaden, Bd. xii. S. 484. 
6 For analysis of synovia by different observers, see Halliburton, " Chem. Physiol.," 
p. 351. 
7 Virchow , s Archiv. Bd. cxxxi. S. 304. 
8 This is unquestionably abnormally high. The fluid was from a case of chronic coxitis. 
