Cerebrospinal Fluid

Cerebro-spinal Fluid. This fluid is contained in the ventricles of the brain and in the central canal of the spinal cord; it is also found forming a kind of water cushion which envelops the delicate nervous structures, and occupying the subarachnoid and subdural cavities. The importance of the layer of fluid in protecting the brain and cord from injury, and the manner in which the amount of fluid is adapted to the capacity of the cranial cavity have been already alluded to. Cerebro-spinal fluid contains but little solid matter. Its specific gravity rarely exceeds 1010; a little proteid is present in it, and there is usually a trace of a substance which reduces copper salts. Cerebrospinal fluid sometimes escapes from the ear in cases of fracture of the base of the skull.