184 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 serum albumin or fibrinogen, nor is there any 

 nucleo-proteid or fibrin ferment. Karely 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 phenylhydrazln 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. 3 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 grms. Water . . . .93*084 



Mucin-like substance . . 0'375) rlQQ 



Other proteids . . . 4*824 / 



Fat .... -282 



Lecithin .... 0*017 



Cholesterin . . . 0*569 8 



Inorganic salts . . . 0*849 (Nacl 0'772) 



1 Yvon, quoted by Halliburton. 



2 For further details consult Halliburton, " Chem. Physiol.," p. 355 ; also "Report 

 of Spina Bifida Committee," Trans. Clin. Soc,. London, vol. xviii. ; and Journ. Physiol. , 

 Cambridge and London, vol. x. p. 232, where the previous literature will be found. 



s Address to the Section of Physiology, Rep. Brit. Ass. Adv. Sc., London, 1896. 



4 Arch.f. d. ges. Physiol., Bonn, Bd. xxxix. S. 193. 



5 Jahresb. u. 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. 



