"We cannot avoid remarking how much it is to be lamented that inquiries of so delicate a nature, affecting the very confines between mind and matter, should have usually fallen into the hands of persons ill qualified for such pursuits, either by mental constitution or by previous experience in the study of subjects involving both physical and metaphysical knowledge. Little is to be expected in such difficult researches from dilettanti of either sex; much less from those whose excessive zeal for novelty and notoriety must necessarily cast suspicion on their statements. Nor can we hope that truth can be elicited from experiments and observations which are made before the public gaze, with more of the characters of a theatrical exhibition than of a sober philosophical investigation." With regard to phantasies, Müller tells us, "When a person who is not insane sees spectres and believes them to be real, his intellect must be imperfectly exercised;" and we must also remember that "mysteries are not necessarily miracles."

THE SYMPATHETIC

Nervous system-also termed that of "organic life" by Bichat, in contradistinction to the cerebro-spinal, or system of "animal life"-consists of a chain of ganglia placed along the vertebral column, and all connected by gelatinous nerve filaments. The dorsal ganglia have the most numerous spinal filaments. The chains of opposite sides are united on the anterior communicating artery-where Ribes discovered a ganglion-by the solar plexus, and below by the ganglion impar on the sacrum. The sympathetic also aids in forming the ganglia on the cerebral nerves, and those on the posterior roots of the spinal which have been alluded to. The account of the histology of nervous matter which we have already given, includes that of the ganglia and branches of which we are now speaking. As an example of the

manner in which the branches are distributed, we shall examine the superior cervical ganglion. It is probably the largest in the body, measuring about two inches in length, and lying on the first three vertebræ. Its branches are-1. Ascending round the internal carotid artery to the cavernous sinus, where they intimately unite with the abducens nerve and some cranial ganglia. As in other positions where they accompany an artery, the twigs entwine closely, "hederæ admodum," and from their softness were termed by Scarpa "nervi molles." 2. Descending to the next ganglion. 3. External, communicating with spinal nerves and their plexus, as all ganglia do. 4. Laryngeal. 5. Pharyngeal. 6. Superior cardiac, which, with those from the middle and inferior ganglia, aid in forming the cardiac plexuses. Organs are usually supplied by the ganglia above them, not by those in their own vicinity, as in the case of the heart, abdominal viscera, testes, &c. The accessory ganglia in and about the heart, and the use attributed to them, have been mentioned in treating of that organ. Occasionally the chain of ganglia seems interrupted by the last dorsal and first lumbar having no communicating filament between them. When an organ becomes increased in size, the sympathetic nerves of it enlarge proportionally, as may be learned by comparing those of the virgin and pregnant wombs. Microscopical investigations are every year adding to the number of ganglia which have of late been found in the tissue of the heart, stomach, intestines, kidney, uterus, &c. It is doubtful if any filaments pass into the limbs, but prabably their arteries may carry some down. The system has been demonstrated in all vertebrates save the cyclostomatous fishes, in which the vagus probably performs its functions.

The Function of the sympathetic is not easy to determine, as so many cerebro-spinal nerves communicate with it. No direct cerebro-spinal nerves reach the in

Sympathetic, and Cerebro- Spinal Nerves of the Head, Neck, and Thorax. 1. Pneumogastric. 2. Its laryngeal ganglion (Sir A. Cooper). 3. Pharyngeal branch of spinal accessory. 4. Gustatory. 5. Internal carotid. 6. Superior laryngeal. 7. Its crico-thyroid branch. 8. Pharyngeal plexus. 9. Left recurrent. 10 and 11. Cardiac branches of pneumogastric. 12. Left pneumogastric in front of esophagus. 13. Posterior pulmonary plexus. 15. Lingual. 16. Glosso-pharyngeal. 17. Spinal accessory. 18, 19, 20. Second, third, and fourth cervical. 21. Phrenic. 22. Fifth cervical. 23. Brachial plexus. 24, 25, 26. Superior, middle, and inferior cervical ganglia. 27, 28, 29, 30. First, second, third, and fourth dorsal ganglia.

testines, yet irritation of the solar plexus will produce vigorous peristaltic movements, except in the tench, as the muscular fibres of the alimentary canal are striated; and their sensibility is shown by the torture which overdistension of the colon produces. It cannot, however, be confidently asserted that these effects are due to the true sympathetic, as it derives many nerve-tubes from the posterior roots of the corresponding spinal nerves, irritation of which will produce identical results. Sensitive impressions, unless intense, are not felt, or are slowly carried along sympathetic fibres, and it was once thought that their purpose was "to cut off sensations." Motor influence is also slowly conducted, and thus what is called rhythmical contraction is produced. As implied by the name-which notwithstanding so many objections has so long adhered to it, it was once supposed to be the exclusive seat of sympathies, harmonizing all nervous actions, and its free communications gave support to the notion. The discovery, however, in 1727, by Pourfour du Petit, that section of the cervical portion gave rise to suffused conjunctiva, which protruded into what

"the haw" and contracted pupil, led the way in ascertaining its most important functions. We have already alluded to the experiments which demonstrated its influence on animal heat and the secretion from glands (see pages 173 and 179); and Brown-Séquard has obtained scarcely less important results as regards its vasomotive action and consequent control over nutrition and other organic processes. He found that placing one hand in ice-cold water lowered the temperature of the other, although no great depreciation took place in the system at large; that this was due to the influence of the sympathetic he inferred from the fact, that stimulation of that nerve in the neck produces contraction of the vessels and diminished temperature, or exactly opposite results to those produced by section of it. A still more convincing experiment was suggested and performed

by the reviewer of the works of Brown-Séquard in the "Natural History Review," July, 1861. A bat's wing is placed in the field of a microscope, and an artery in it accurately measured with the eye-piece micrometer; now if ice be applied to the opposite wing the vessel can be seen to contract or even close completely. The discovery of the constriction of blood-vessels by stimulation of the sympathetic was made also simultaneously by Brown-Séquard, Bernard, and Dr. A. Waller.

The occurrences which these physiologists have observed to take place when the cervical portion of sympathetic is divided, and when it is stimulated by galvanism, are here compared:

GALVANIZATION.

Pupil dilates.
Eyelids partially open.

Eye protrudes.
Mucus decreases.

Vessels contract, flow of blood
decreases.

Temperature decreases. Sensibility and irritability decrease and disappear sooner after death.

Strychnia canses convulsions less readily.

Muscular galvanic current is weaker.

Rigor mortis comes sooner, lasts less time.

Putrefaction comes sooner. Injection of arterial blood restores contractility for a shorter time.

To account for the increased action which occurs when the sympathetic is injured, it is suggested that it may have an inhibitory or preventive function. Section of the spinal cord leads to effects quite similar to those produced by that of the sympathetic, and it is not certain