Pus, Wedl regards, and he agrees with Vogel, Paget and nearly all modern observers in this particular, to be a true degeneration of an inflamatory plasma, and not simply, as frequently supposed, an increase of white corpuscles of the blood. Mucus, as it is met with in pathological products is but modified pus. It contains more mucin in its composition, but the corpuscles are identical, since acetic acid will render nuclei apparent in both.

Formerly all small elevations occurring in any tissue were denominated tubercle. Now we design as tubercle, masses analogous to those found in the lung, which are clinically connected with a certain set of well-marked symptoms. The form tubercles present is very various. Some are small grey elevations, others distinctly isolated yellow masses, some are really infiltrations into tissues, others are merely loosely surrounded by the parts in which they are deposited. Yet all these varieties agree in this particular, that they never contain vessels, and that they consist microscopically of granules, a firm proteinaceous blastema in flakes, of nuclei and imperfectly formed granular bodies and cells. The difference in their external appearance led Rokitansky to consider grey and yellow tubercles as two distinct varieties of fibrinous lymph, and induced Robin to advocate the singular view that tubercles are never grey, but that true tubercular matter is always yellow. The difficulty of distinguishing between tubercles and some forms of degenerate lymph, and arrested cell formation is sometimes very great; and, in consequence, many pathologists have sought for special corpuscles by which tubercle might be recognised. Thus it was that Lebert gave the name of "tubercle corpuscle" to the peculiar irregular granular bodies without distinct nuclei and uninfluenced by acetic acid, so frequently met with in tubercular masses. Wedl does not consider these bodies of much diagnostic importance, for he affirms that he has met with the same bodies in the products found in the intestines in typhoid fever, and regards them only as cells arrested in their development. He considers, indeed, the microscopical diagnosis of tubercle only possible by a system of microscopical

exclusion.

*See Bernard and Robin on the Blood. Phila. 1854.

"Positive, characteristic elements tubercle does not possess. The microscopical diagnosis must therefore be made by exclusion. If we meet with a pathological new-formation consisting only of the above named constituents and fully formed cells of various shapes, if blood vessels or blood spaces, or a fibrous stroma enveloping the cells be absent, we are sure that it is a pure tuberculous formation we have before us. If, on the other hand, the imperfecly formed elements are only found in part of a new formation, for example, of a cancer, while perfectly developed cells of different shapes, along with blood vessels and areolar tissue are seen in other portions, we would regard this formation as a cancer, in part of which the organization had not progressed very far, and had remained, as it were, stationary, in the same low grade as it does in the formation of tubercle." (p. 367.)

When tubercle has existed for any length of time, its general tendency is to soften, or else it changes into a calcareous substance. Softened tubercle resembles pus, but does not contain the same corpuscles as the latter; for, examined microscopically, it consists of molecules, oil globules, free nuclei and imperfectly developed cells. In calcified tubercle, Wedl has found, besides the calcareous salts deposited in the centre of the hardened mass, oil globules, brownish pigment and crystals of cholesterine.

As closely connected with tubercle, both in regard to its mode of development and structure, Wedl describes the deposits that take place in typhoid fever in Peyer's glands, in the mesenteric glands, and between the mucous and muscular tissue of the intestine. The elements he has observed in these infiltrations are cells 0.008 to 0.024 mm. in size, of a roundish form, and containing one or sometimes several oval nuclei. These cells also enclose many fine granules, sometimes, also, oil globules, which conceal the nucleus and fill up the whole of the interior of the cell. Besides these roundish cells, which are the most abundant, he finds in typhoid fever infiltrations, many spindle-shaped cells with large oval nuclei and nucleoli. In many cases, instead of masses of fully developed cells, Wedl states that he has met with granular bodies, similar to the ones Lebert has described as "specific" tuberclecorpuscles. On the surface of the ulceration, the organic newformation is not distinct. Here nuclei of varying size and a few oval cells are found imbedded in a molecular mass containing also fat-globules.

The last of the new-formations which Wedl describes is cancer. We cannot follow our author in his elaborate description of the

various forms of cancer met with in the human economy, but will merely state, that he is one of those who deny the specificity of the cancer cell. The microscopical diagnostic marks of cancer on which Wedl seems to lay most stress, are the study of the evolution or involution of the cells, or in other words, their vital phenomena, their growth, their metamorphosis, their multiplication, and the formation of other tissues in the morbid structure. Without entering here into the much vexed question of the cancer cell, we would yet, in this particular, venture to suggest to the author, the employment in his investigations of higher magnifying powers than he seems to have used.

If in conclusion we were called upon to state our impression of the general merits of Prof. Wedl's work, we must express the sincere pleasure we derived from its perusal. The work is, as far as we are aware, the first that has as yet appeared upon. pathological histology, but independently of that, it will always retain a high stand on account of the many original and carefully made observations it contains. The style is plain and distinct, the wood-cuts are the best we have seen anywhere, but in the getting up of the book we miss much a proper index.

DAC.

A Practical Treatise on Foreign Bodies in the Air Passages. By J. D. Gross, M. D., Professor of Surgery in the University of Louisville, &c. With illustrations. Philadelphia: Blanchard & Lea, 1854.

It is rather surprising, considering the number of monographs which we possess on almost every subject, that no complete one has ever appeared, in any language, on foreign bodies in the air passages. The only paper mentioned by Dr. Gross as even approaching such an attempt, is the "Memoir on Bronchotomy," by Mons. Louis, published in 1759, in the Transactions of the Royal Academy of Surgery. Celebrated as this paper was in its day, few practitioners, we suspect, knew of its existence, much less were able to use it, as a work of reference, previous to its mention by our author. Several papers, it is true, have appeared in Great Britain, upon the subject; from none of these, however, can much information be obtained. A short memoir, by Dr. H. G. Jameson, of Baltimore, published in the American Medical

Recorder, is spoken of as being, for a long time, one of the best accounts of the subject in the English language. When we consider the great need of such a work, the comparative frequency of such accidents, the general ignorance of the symptoms they cause, and of the proper medical and surgical treatment to be pursued, we cannot too highly estimate our obligations to the author for the able and elaborate treatise he has given us. His zeal and industry in collecting, arranging and analysing the numerous cases, scattered through the medical journals of this and other countries, in addition to those which now, for the first time, are given to the profession, are deserving of all praise. We have read his treatise through, and we do not hesitate to say that it is in every respect a work, of which, as Americans, we have great reason to be proud.

Chapter 1st discusses the nature of those substances which enter the air passages-the alteration which they are liable to undergo from their retention-their most common situation, and finally, the mode by which they enter and are expelled.

Since the publication of Dr. Gross's treatise, two cases have been recorded which, as they belong to a class not mentioned by our author, we shall briefly mention. One of these was, the introduction, while coughing, of a plug of thick mucus into the air passages of a child, producing the usual symptoms caused by a foreign substance there; tracheotomy was performed in vain, the patient dying a short time afterwards. We record the case in the present number. The other instance alluded to* is that of a lad, eight years of age, who, while playing, was said to have been struck by one of his playfellows. When arrived at his home, a minute or so afterwards, his struggles became so violent that he could scarcely be held. When seen by Dr. Bell, a half an hour after the seizure, his countenance was livid and he was making some feeble struggles, evidently death-throes. Tracheotomy was immediately performed, and artificial respiration afterwards attempted, but without effect, as he gave but two gasps after the operation. Upon examination a diseased bronchial gland, one inch long, was discovered under the epiglottis, and extending from the rima glottidis into the larynx. It had become de

• Medico-Chirurgical Transactions, vol. xxxvi.

tached from its bed by ulceration around it, which opened a way also for its passage into the trachea. The blow complained of was no doubt the means of forcing it from its position into the trachea, from which place it was driven into the glottis by strong expulsive efforts.

The case is an exceedingly interesting one, in a medico-legal point of view. Had no autopsy been made, the death would have been attributed to any other cause but the true one, and most serious consequences might have been the result to the boy who struck him, if the case had gone before a jury.

The alteration of foreign bodies in the air passages is of great practical interest to the surgeon. Though many vegetable and animal substances are liable to be occasionally softened and disintegrated by the combined action of heat, moisture and their frequent change of position in the lungs, Dr. Gross very properly reprobates, where the symptoms are severe, the absurdity of trusting to such a contingency. The place where a foreign body becomes arrested will be influenced, materially, by its size, form, and weight. When it is stopped in the larynx it may lodge either in the ventricles or between the vocal chords. It rarely is arrested in the trachea, but, having arrived at its extremity, descends most generally into the right bronchial tube. This latter circumstance is owing to the fact that the septum, at the root of the trachea, is not in the central line, but to the left of it. Hence, bodies, particularly those of considerable bulk, as they strike upon this ridge, will naturally fall over to the right side.

Most substances enter the air passages through the glottis. They may obtain entrance there, however, in many other ways; through the pharynx by ulceration, by wound of the throat, and through the walls of the chest. Cases are given of these different modes of admission.

Expulsion of foreign substances generally takes place at the glottis; occasionally, however, they are discharged through an abscess or fistula in the walls of the chest. Dr. Stanski asserts that he is acquainted with as many as twenty cases where such a result took place. The author reports an interesting case, where a sprig of a juniper tree, which had passed into the windpipe of a young child, was discharged a year afterwards, through