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his relatives. He was further sentenced to the galleys for life, from which, however, he was soon released. Some information is added respecting Monsignore Guerra, who was not Beatrice's lover, but was in all probability an accomplice in the murder of Francesco; and of Farinaccio, the celebrated lawyer. All these are interesting, and abound in traits illustrative of the manners and morals of the time. But the necessities of space and time compel us to content ourselves with referring the curious reader to Signor Bertolotti's work.

The true story of Beatrice and her crime has now been told for the first time, and may fairly be concluded with the remark that there is no ground whatever for all that has been said by so many writers to the effect that the condemnation was in any degree caused by a desire on the part of the Papal Government to confiscate the Cenci wealth. The property was not confiscated, as is clear from the testamentary dispositions of the culprits; and it all might have been confiscated according to the habits of the time and country by allowing the prisoners to compound, or, in other words, buy themselves off. The fact is that the Pontiff, Clement VIII., hesitated long between justice and mercy, and was at last suddenly determined in favour of the former by the tidings of another similar crime recently committed by a member of another noble race—the murder of his mother by one of the Santa Croce family.

ART. III.-1. Manual of Human and Comparative Histology.

Edited by S. STRICKER. Microscopic Anatomy of the Nervous System. By Max SCHULTZE. Translated by HENRY POWER, M.B. Issued by the New Sydenham Society.

London : 1870. 2. The Principles of Mental Physiology. By WILLIAM B.

CARPENTER, C.B., M.D., LL.D., F.R.S. London: 1876. 3. The Physiology of Mind. By HENRY MAUDSLEY, M.D.

1876. The process which is adopted when an electrician transmits

messages along the telegraph wire, and that which nature pursues when signals are passed through the instrumentality of nerve influence in the living animal body, are so remarkably alike that the best known of the two methods of signalling may be advantageously referred to as a first step in the explanation of the one that is less familiar and less obvious.

The electrical engineer, in his telegraph work, employs two quite distinct classes of instruments. He first stretches out long strands of iron wire for the conveyance of the message that he has to transmit, and he then contrives a battery of galvanic cells to generate the electric force that is to be sent streaming along the wires. Those stretched metal strands, as every one is aware, are kept perfectly distinct from end to end. They are either suspended in the air from insulating supports of porcelain, or they are clad in an investing sheath of electrically impervious substance, to confine the fleet messenger to its appointed path. The electric stream which travels along the wires is provided in the battery by the action upon

each other of some such substances as metal, water, and acids, or salts, which produce changes of physical state amidst their own molecules when they are brought into contact, and, as a part of those changes, set free currents of force which was before employed in preserving the original state of the several constituents. The currents of the emancipated force are turned on from the battery to the wires whenever a signal or message is to be transmitted along them.

In the organised framework of the animal body, in a similar manner, isolated strands are laid down for the conveyance of nerve influence, and batteries are provided for its production. The conveying strands are seen, when the structure of the organisation is examined by curious observers, in the form of white glistening fibres or threads, which are designated "nerves.' The batteries are also discoverable amidst these threads. They appear under the aspect of tumours' or • knots' of the nerve-substance, and are thence termed 'gan

glia.' The nerve-ganglia occur in considerable abundance in most parts of the body; but their favourite seats, or focal centres, are the brain, and the spinal cord which is a prolongation of the brain. The spinal cord and brain are, indeed, vast masses of nerve-ganglia connected together by a tangle of threads.

The minute anatomy of this nerve-structure and brainstructure of the animal body is, however, one of the most marvellous of the revelations that have been made in consequence of the discovery and employment of the microscope; the ultimate elements that are concerned are of almost inconceivable minuteness. Nerve-threads may be microscopically brought within the reach of the eye which are of such exquisite fineness that fifty thousand of them can be ranged side by side within the limit of an inch. Of such fibres it would take something like one hundred and twenty millions to make up a cord of the diameter of a pencil. At the extreme ends of these minute nerve-fibrils, where they are severed from each other, each fibril is moulded in the form of a round or flattened rod, which is composed of soft albuminous substance, and which is destitute in this situation of all external covering. It is simply a thread of albuminous pulp, drawn out like the threads of viscid glue which may be formed from warm gelatinous solutions. În this state it is technically called the “axis-cylinder,' or core, of the nerve fibre.

When, however, several of these ultimate nerve-cores are brought into close contiguity for convenience of package, they are coated over, before they are allowed to touch each other, with a mixture of albumen and fat. This coating of the nervefibre is designated the medullary substance of Schwann, because it was first observed by a distinguished German physiologist of that name. Its purpose is obviously analogous to that of the gutta-percha covering of telegraph wires destined to be buried in the earth or to be sunk in the sea.

It serves to isolate each strand. After the nerve-fibril has been coated by this insulating pulp, it is then further enclosed in a kind of nerve-skin, or sheath, which is known as the neurilemma.' Each glistening nerve which is traced by the anatomist in the human frame is made up of a multitude of these coated and sheathed fibrils, of which every one is kept distinct and apart from the rest, from end to end. In this elaborate piece of organisation, however, it must be understood that the membranous sheath and medullary coating are merely mechanical incidents of the structure; the axis-cylinder, or core, is the effective part upon which the transmission of the nerve influence depends.

The ganglionic, or force-originating portion of the apparatus, is of an altogether different character ; but it is of an equally elaborate and marvellous design. It consists of globular vesicles of exquisitely filmy membrane, containing in their interior cavities a soft granular pulp of a reddish-brown tint. These vesicles are of a larger diameter than the elementary fibrils of the nerves, and, though generally of a globular outline, run out very often into angular corners or horns. At these horns the axis-cylinder, or core, of some adjacent nervefibril is brought into close connexion with the granular pulp, either by the free passage of the one into the other, or by the pressing up of the thin filmy nerve-sheath of the fibril against the equally delicate membrane of the globule.

These ganglion-globules of the nerve-apparatus are invariably deposited within the meshes of a network of hair-fine blood-vessels, in the midst of which they are grouped and distributed in such a way that, as the abundant blood-streams course along through the netted channels of the vessels, the globules get bathed and saturated by the streaming blood. The blood transudes through the filmy walls of its own vessels and of the ganglion-globules, where these lie in close contact. The result of this drenching of the nerve-globules with the blood is, that their granular pulp is continually reinvigorated and renewed. The force which they originate is extracted from the blood. The ganglion-masses of the most active parts of the nervous apparatus, such as the brain, indeed receive a tenfold larger supply of blood than any other portion of the living organisation of equal size; and if the flowing stream is suspended for even a passing instant, all brain-power is simultaneously lost.

From all this it therefore appears that the ganglion-globules of the nerve-apparatus are the batteries in which nerve influence is produced, and that that nerve influence is set free as a consequence of destructive change set up in material furnished by the blood. Rich, complex food, brought to the ganglion-globules by the streaming currents of the blood, is changed, in the interior of those globules, into the red granular pulp; and then the red pulp is resolved into simpler states, setting free force capable of being turned to account, and of being discharged as currents of nerve influence into the associated threads, whenever messages are required to be sent along them in the signalling service of the economy.

As in the case of the electric telegraph signalling batteries are provided at each end of the line, in order that messages may be sent in both directions, to and fro, so also there are ganglionmasses at each end of the nerve-threads in the animal body. Wherever impressions have to be transmitted from external regions of the body in to the central nerve-masses of the frame, as in the case of the eye, the ear, and the sensitive skin which is the outer boundary of the organisation, abundant ganglion-globules are laid down in connexion with the outer extremities of the nerve-fibres. No nerve-current, indeed, is possible without the presence and influence of this originating part of the apparatus. There are ganglion-masses associated with the outer extremities of the nerve-fibrils in all the external organs of sense. This is indicated at once by the colour or tint of the nerve-structure where such masses occur. The ganglionic, or originating, part is always of a grey hue on account of the presence of the red granular pulp, and of abundance of blood. The mingling of the red blood and granules with the white nerve-pulp converts its whiteness into grey.

The fibrous, or simply transmitting, part of the nervestructure, on the other hand, is in all cases white, and not grey, because it is destitute alike of the red blood and red granular pulp.

The nerve-pulp, which is prepared out of the blood in the ganglion-globules, has naturally been an object of constant curiosity to chemists. They have examined its composition very carefully in the hope that they might by that means ascertain the secret of its magical power. The result of the examination is that this pulp has been found to be composed chiefly of an albuminoid substance of a very complex nature, to which the name protagon' has been given. So far as the analysis of this organic base of the nerve-pulp has been found practicable, it has appeared that each of its molecules is built up of carbon, hydrogen, nitrogen, phosphorus, and oxygen. 232 atoms of carbon, 240 atoms of hydrogen, 4 atoms of nitrogen, 22 atoms of phosphorus, and 22 atoms of oxygen are contained in each ultimate molecule of the protagon. The large number of the elementary atoms that have been drawn upon for the construction of this molecule efficiently expresses the elaborate complexity of the substance, and in some measure accounts for the large store of potential, or latent, energy which it contains, and which it yields up as active and effective force when it is resolved back into its elements. Its special fitness to be so decomposed into its elements is manifested in the fact that of the 520 atoms of which each protagon molecule is composed, 494 are the fiercely combustible principles carbon, hydrogen, and phosphorus, which are at all times so ready to dissolve their state of union with other bodies, or amongst themselves, in order to combine with oxygen. The oxygen which effects the decomposition of the protagon molecules in the ganglion-globules is supplied in abundance in the streaming blood. Each red corpuscle of the blood takes up a charge of oxygen from the breath as it passes through the air-cells of the lungs, and then delivers that over to the ganglionglobules of the nerve-apparatus, as it traverses the meshes of the capillary vessels. It is in this sense that the blood blows up the flames of the nervous activity, at the same time that it furnishes nourishment to the nerve-substance. With each discharge of nerve-force that occurs from the nerve-batteries, atoms of carbon, hydrogen, and phosphorus are snatched out of the protagon of the nerve-pulp by the oxygen conveyed to them by the blood-corpuscles. The nerve-influence set free in the ganglion-masses is as essentially a product of the oxida

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