CII YLE — CEREBROSPINAL EL UID. 1 83 
and does not clot spontaneously, but only on addition of fibrin ferment, 
such as is contained in serum. Traces of urea are present but no sugar, 
although a slight reduction of Fehling's solution is sometimes obtainable. 
This is probably due to paralactic acid. 1 
The following analysis of aqueous humour is by Lohmeyer: 2 — 
En 1000 parts- 
Water .... 986-87 
Proteids . . . . L22 
Extractives . . . . 4 -21 
XaCl . . . . 6-89 
Other salts .... 0"81 
Pericardial fluid is a form of lymph which is found in small 
quantity within the sac of the pericardium. Peritoneal and pleural 
Quids, and the fluid of the tunica vaginalis, are not normally present in 
sufficient quantity to be collected and analysed. Pericardial fluid 
contains rather less proteid than ordinary lymph (2'28-2"55 per cent.). 3 
Pericardial fluid, as obtained from the horse or ox, is a yellowish 
fluid, resembling serum in appearance and in its general composition, 
but it contains fibrinogen.' 1 It usually has no leucocytes, nor is it 
spontaneously coagulable, but it coagulates on the addition of ferment or 
of nueleo-proteid. 
Chyle has nearly the same composition as lymph, but it contains 
more solid matter, the increase being chiefly in fats, but also in proteids. 
The following table from Hoppe-Seyler gives its general composition in 
the dog and a comparison with the serum of the same animal. 
Chyle of 
Serum of 
Dog. 
same Dog. 
Water 
90-67 
93-60 
Fibrin 
0-11 
Albumin and globulin 
2-10 . 
4-.~>2 
Fat, lecithin, cholesterin 
6-48 
0-68 
Other organic substances 
0-23 
029 
Salts 
0-79 
0-87 
The ether extract of chyle was found by Hoppe-Seyler to contain, 
per cent. : — 
Cholesterin . . . .14-09 
Lecithin . . . . 8 -8 4 
Fats ..... 77-07 
There is also, according to Hoppe-Seyler, a small amount of soap in 
chyle. The amount of urea and of sugar is about the same as in lymph. 
The cerebrospinal fluid, although resembling lymph in its appear- 
ance, and probably in being formed by transudation from the blood 
vessels, differs from lymph chemically in certain important details. 
Although cerebro-spinal fluid is not obtainable normally in sufficient 
amount for analysis, the fluid of a meningocele appears to be nothing 
but an accumulation of the normal fluid, and has been frequently 
analysed, and the fluid of hydrocephalus has also been used for this 
purpose. Cerebro-spinal fluid as thus obtained is a clear, colourless 
1 Kuhn, Arch./, d. ges. Physiol., Bonn, 1888, Bd. xi. S. - 200 ; Griinhagen, ibid., S. 377. 
2 Gorup-Besanez, "Lehrbuch," 1878, S. 401. 
3 Hoppe-Seyler, "Physiol. Chem.," 1881, S. 605. 
4 For analyses of pericardial fluid from the horse, and also for the analysis of various 
dropsical fluids which teud to accumulate in the serous cavities of man, see Halliburton, 
"Chem. Physiol.," pp. 33S and 339, and Brit. Med. Joura., London, 1890. 
