very pale around the hæmoptysical induration; sometimes, however, it is rose-coloured, or even red, as if tinged with fresh blood; but, even in this case, the circumscription of the indurated part is equally distinct.

"The indurated portion is of a very dark red, exactly like that of a clot of venous blood. When cut into, the surface of the incisions is granulated as in a hepatized lung; but in their other characters, these two kinds of pulmonic induration are entirely different. In the second degree of hepatization, along with the red colour of the inflamed plumonary tissue, we can perceive distinctly the dark pulmonary spots, the blood-vessels, and the fine cellular intersections, all of which together give to this morbid state the aspect of certain kinds of granite, as has been already observed. The same thing is observable in the third stage of peripneumony, and even when the infiltration of pus has converted the lungs into a yellowish mass. In the induration of hæmoptysis, on the contrary, the diseased part appears quite homogeneous, being altogether black, or of a very deep brown, and disclosing nothing of the natural texture of the part, except the bronchial tubes and the larger blood-vessels. The latter have even lost their natural colour, and are stained with blood." P. 62.

In scraping the incised surfaces of these parts, we detach a small portion of very dark half-congealed blood, but in a much less proportion than we can press out the bloody serum from a hepatized lung. Sometimes the centre of these indurated masses is soft, and filled with a clot of pure blood.

This morbid affection appears to our author to be evidently produced by an effusion of blood into the parenchyma of the lungs in other words, into the air cells. From its exact resemblance to the effusion that takes place in the brain in apoplexy, M. Laennec has given it the term pulmonary apoplexy. The lungs and brain, however, are not the only organs in which a similar effusion may occur. It is seen to take place instantaneously in the subcutaneous cellular tissue between the intestinal and ocular tunics, among the muscular fibres of the heart, and under the cellular coverings of the pancreas and kidneys. "In a case of fatal apoplexy," says M. Laennec, "I have found large effusions of blood in the cellular membrane of every limb, of the trunk, and in that surrounding most of the abdominal viscera."

"The hæmorrhagic induration of the lungs is as easily distinguishable from the congestions that take place after death, as from the alterations produced by peripneumony. The sanguineous congestions of the dead body consist of an accumulation of blood intermixed with serum, often spumous, which flows plentifully on an incision of the part, and tinges the lungs of a livid or vinous colour. Being the mere consequence of gravitation, the engorgement is found most considerable in the most depending parts of the lungs, and Vol. II. No. 8.

5 M

gradually lessens towards the superior parts. Where most engorged, the part still retains some crepitation, and the incised surfaces are never granulated, even when the congestion is so great as to destroy the spongy character of the lung. By washing, we can, in every case, remove all the blood, and restore the lung to that sort of flaccidity which it possesses when compressed by a pleuritic effusion. The engorgement of hæmoptysis, on the contrary, is accurately circumscribed, very dense, dark-red or brown, granulated, and almost dry when incised, and grows pale by washing, but without losing any part of its consistence." P. 64.

Whatever may be the severity of the case, resolution seems to take place with considerable facility, since we find a great many instances of cure after very severe hæmoptysis. The above is the condition of parts in all these severe cases; but when the symptoms are moderate, and the hæmorrhage slight, the only morbid alteration of structure is a reddening and thickening of the bronchial membrane, which, in these cases, seems to permit the transudation of the blood.

Therapeutical matters enter not into the composition of this valuable work; but we may just remark, en passant, that we have found practitioners in this country too timorous in respect to the exhibition of superacetate of lead and opium in hæmoptysis. We have happened to be much in the way of this disease, and we have found such decided benefit from the combination above mentioned, and that in large doses, that we beg to impress, the circumstance on the memory of our younger brethren. Without having so accurate an idea of the real pathology of the disease as Laennec has since imparted, we had long been convinced that the blood came from the capillary vessels, and consequently that those remedies which are known to have an influence on the capillary system, were indicated. We have often seen men bled day after day, and take digitalis, infusion of roses, and sulphuric acid, in hæmoptysis, without materially lessening the flow from the lungs; while, on the other hand, a moderate bleeding, followed by superacetate of lead and opium, has restrained effectually some of the most alarming discharges of blood which we ever witnessed.

But we must now reluctantly take leave of Dr. Laennec and his translator. To the former we have often paid the tribute of our respect for his talents, and unwearied exertions in the science of pathology. In Dr. Forbes the public has a physician of native genius and acquired knowledge-the profession, a member of zeal, honour, and integrity.

VIII.

On the Nerves; giving an Account of some Experiments on their Structure and Functions, which lead to a new Arrangement of the System. By CHARLES BELL, Esq. (From the Philosophical Transactions.) Quarto, pp. 30. One Plate. London, 1821.

WITHOUT physiology—that is, without a perfect knowledge of the laws by which the healthy functions of our system are governed, we cannot expect to make much progress in pathology. Every person, therefore, who elucidates a known, or discovers a new law in the animal economy, contributes his mite to the advancement of the science of medicine-even if that law should not appear to bear on any point of pathology or practice at the time.* No man, in this country, works harder in unravelling those mysteries of the nervous system which puzzles our senses, than the present distinguished teacher in the venerable school of the Hunters.

Mr. Bell remarks, that when the physiologist sees two distinct nerves ramifying over the face-three nerves, from different sources, going to the tongue-four to the throat-and nerves in most perplexing intricacy to the neck; when he finds one nerve with numerous ganglia upon it, and another without them—when, in short, after a minute dissection of the nervous system, he finds a mesh, or network, spreading every where, it is not surprising that the seeming intricacy and confusion should make him, in despair, resign inquiry. Mr. Bell, however, by long dissection and study, has been able gradually to decipher some of the abstruse language of the nervous system, and hopes, sooner or later, to come to a comprehension of the whole.

The present inquiry is limited to the nerves of respiration, which our author thinks, form a system of great extent, comprehending all the nerves which serve to combine the muscles employed in the act of breathing and speaking. Tranquil breathing gives a very limited view of the respiratory muscles. But if a man be excited by exercise or passion, or by whatever accelerates the pulse, the respiratory action is extended and increased; and, instead of the almost imperceptible motion of the chest, as in common breathing,

When the air-balloon was first discovered, some one flippantly asked Dr. Franklin what was the use of it? The Doctor answered, in the Socratic manner, by asking another question:-What is the use of a new-born infant ?—it may become a man."

the shoulders are raised at each inspiration, the muscles of the throat and neck are violently drawn, and the lips and nostrils move in time with the general action. If he does not breathe through his mouth, the nostrils expand, and fall in time with the rising and falling of the chest, whilst the curious apparatus of cartilages and muscles of the nose, are as regularly in action as the levator and depressor muscles of the ribs.

"It is quite obvious, that some hundred muscles thus employed in the act of breathing, or in the common actions of coughing, sneezing, speaking, and singing, cannot be associated without cords of connexion or affinity, which combine them in the performance of these actions; the nerves which serve this purpose I call respiratory nerves." P. 6.

Mr. Bell observes, that the nerves of all animals, including man, may be divided into two systems or classes-into those destined for the organization necessary to life and motion in an animal-and those which supply organs superadded as the animal advances in the scale of existence. The nerves of the spine, the tenth or sub-occipital nerve, and the fifth or trigeminus, belong to the simple and symmetrical system.

"All these nerves agree in these essential circumstances; they have all double origins; they have all ganglia on one of their roots; they go out laterally to certain divisions of the body; they do not interfere to unite the divisions of the frame; they are all muscular nerves, ordering the voluntary motions of the frame; they are all exquisitely sensible; and the source of the common sensibility of the surfaces of the body: when accurately represented on paper, they are seen to pervade every part ; no part is without them; and yet they are symmetrical and simple as the nerves of the lower animals.

"If the nerves be exposed in a living animal, those of this class exhibit the highest degree of sensibility; while, on the contrary, nerves not of this original class or system, are comparatively so little sensible, as to be immediately distinguished; insomuch that the quiescence of the animal suggests a doubt whether they be sensible in any degree whatever. If the fifth nerve and the portio dura of the seventh, be both exposed on the face of a living animal, there will not remain the slighest doubt in the mind of the experimenter which of these nerves bestows sensibility. If the nerve of this original class be divided, the skin and common substance is deprived of sensibility; but if a nerve not of this class be divided, it in no measure deprives the parts of their sensibility to external impression." P. 10.

The nerves connecting the internal organs of respiration with the sensibilities of remote parts, and with the respiratory muscles, are distinguished from the above by many cir

cumstances. They have not double roots, nor ganglia on their origins. They come off from the medulla oblongata and the upper part of the spinal marrow, and from this origin they diverge to those several remote parts of the frame which are combined in the motion of respiration. These are the nerves which give the appearance of confusion to the dissection, because they cross the others, and go to parts already plentifully supplied from the other system. The following are respiratory nerves, according to their functions.

1. The par vagum, distributed to the larynx, lungs, heart, and stomach, associating these organs together, though they are plentifully supplied with nerves from other sources.

"Comparative anatomy would lead us to infer that this nerve is not essential to the stomach, as it does not exist but where there are heart and lungs to associate with a muscular apparatus of respiration. That the stomach must be associated with the muscu lar apparatus of respiration, as well as the lungs, is obvious, from the consideration of what takes place in vomiting and hiccough, which are actions of the respiratory muscles excited by irritation of the stomach." P. 11.

2. Respiratory Nerve of the Face, or portio dura of the seventh. This nerve also goes off from the medulla oblongata, spreads wide on the face, and on it solely depend all those motions of the nostrils, lips, and face generally (as will presently be shown) which accord with the motions of the chest in respiration. By the division of this nerve the face is deprived of its consent with the lungs, and of all expression of motion.

3. Superior Respiratory Nerve of the trunk, or spinal accessory, which has puzzled physiologists on account of the singular course which it pursues. After arising from the upper part of the spinal marrow, in a line with the roots of the other respiratory nerves, it passes into the skull, and comes out with the par vagum, descending upon the neck, supplying muscles of the shoulder already profusely supplied with nerves from other sources. This nerve controls the operations of the muscles of the neck and shoulder in their office as respiratory muscles, when by lifting the shoulders they take the load from the chest, and give freedom to the expansion of the thorax. When this nerve is cut across in experiments, the muscles of the shoulder, which are in action as respiratory muscles, cease their co-operation, but remain capable of voluntary actions.