formed. In this case, either both plates of the skull gradually retreat and sink in, after the brain (and this generally takes place on the forehead first) and thus the head becomes smaller in general, as our daily observations upon old people may convince us: Or the skull itself becomes thicker, either by a new mass of bone forming itself in the place of the shrunken brain; or the inner plate alone shrinking, a fresh mass of dipploë is collected between the two plates of the skull. Hence it happens that in old age the head always becomes smaller or heavier, and sometimes both,

It is not only in a state of health that the skull is modified by the brain: The disease of the brain will also produce a diseased form of skull, which thus serves as a diagnostic sign of the disease of the brain.

In an hydrops internus, the ossa parietalia are pushed outwards: But at first the water presses downwards, makes the basis cranii flatter, and the orbits narrower, so that the eyes are pressed out.

Gall produced the skull of a boy seven years of age, who died of a consumption of the brain; the skull was unusually small, and Gall stated this as an instance that frequently occurs, and shewing how the growth of the

skull

skull was impeded by the disease of the brain,

Another phænomenon attending the shrinking of the brain, was stated by Gall to be not unfrequent, and leading to the same conclusion: that is, the hollowness and deepness of the orbit of the eye, the lamina of which retreats backwards with the shrinking brain.

But the more important cases on which Dr. Gall relies are those of lunacy, confirmed madness, and a disposition to commit suicide. With respect to these, Gall professes to have been led by his theory of the brain and of its organs to adopt modes of cure which have been successful, and which promise to be of great value to the practising physician.

When lunacy has lasted long, one part of the brain shrinks away after the other, till confirmed incurable insanity is the consequence. The effect of this is, that the skull becomes always smaller and generally more heavy, thick, and dense; from the accession of bone and dipploe, as before stated. By lunatics too the same appearances take place.

Gall has also found in suicides, the same thickness and weight of the brain; and he ascribes self-murder to a general disease of the whole brain, and considers this fatal deed as

generally

generally within the sphere of the physician rather than of the moralist. He ascribes therefore no organ to the love of life.

Where the disease of the brain is topical, there too the skull is partially affected. Where the brain is generally diseased, the skull betrays the evil by its general appearance; it ceases to grow, and a remarkable smallness and thickness of skull is apparent, not only in idiots, but in whole races that have been brutalised by long subjection and slavery.

These observations were made by Dr. G. as the result of many years practice, and with a particular attention to the subject. Here too he related a number of cases, the enumeration of which would be here irrevelant. He accompanied these statements by the production of skulls of very unusual thickness and weight one of them, which weighed twice as much as another skull of an adult which was produced for other purposes, he stated to be that of a poor man, who had all his life been known as an industrious, sober, and honest man, but of a melancholy temperament: on a sudden, tho' no motive, adequate to the action, could be discovered by those who were acquainted with him, he killed his wife, several children (all of whom he loved tenderly) and then himself. G. stated

expressly

expressly, that he had never known either a lunatic, madman, or self-murderer, on whose skull sonie unusual appearance either in the particular formation, or general texture was not discoverable. He considers the fundamental causes of these diseases to lie in the brain, which however he supposes to be strongly affected by the climate and weather. Among the external causes, he imputes much to a moist atmosphere, and has remarked fatal effects in Germany from a prevalence of the south wind.

CHAP.

CHAP. VI.

OF ORGANOLOGY AND ORGANOSCOPY.

HAVING shewn by arguments a priori, that we ought not to be content with a general reference of the mind as one faculty, to the brain as one organ; but that as we are conscious of diverse powers of mind, and observe that the brain is a various substance; we may assume in both equally, a distinction of parts, tho' those parts may be ultimately so united as to become one; we ought hence to seek at least to ascertain the relation of these several parts to each other: And having proved that the skull is modelled by the brain, and that therefore we may avail ourselves of the hardness and permanent form of the one, to discover what the softness and perishable nature of the other would not permit our finding directly; we might proceed now to the statement of those organs individually but it will be necessary previously