croscopical characters as follows: "The structure of the tumour possessed a distinct capsule, to which I have alluded above. This is rarely found in colloid tumours, except in the omentum. The smaller nodules on the bladder and elsewhere did not possess any very distinct capsule. When examined under the microscope, sections of the tumour exhibited the nucleated cells, called colloid corpuscles by Lebert. Large compound cells were also observed, containing several granular nuclei of various sizes, as well as nucleated cells. The fibrous tissue was also distinctly seen."

Melanosis need scarcely be referred to as a separate form of cancer, for Carswell demonstrated that it was but any other form stained accidentally by pigment; thus, in the lungs, eye, skin, &c., it most frequently occurs, for they normally contain pigment.

As regards the nature of cancer much uncertainty prevails, some modern pathologists believing that its germs or nuclei are carried in the blood (cancremia), others that it is only a local perverted nutrition. It is only in the very latest stages, when the cancer is being broken up, that any microscopical or chemical examination discovers any alteration in the blood; then nuclei and other debris, and fibrin to the amount of 17 per 1,000, have been found.

Physical Alterations of texture are frequent results of perverted nutrition, and examples of each kind will be readily remembered. 1. Hardening is often the result of chronic inflammation, as in cirrhosis of the liver, lung, and other organs, or may follow the frequent determination of blood-the ivory-like condition of the inner table of the skull, especially of the insane, is an example. 2. Softening is nearly always a sequence of inflammation, the increased effusion of serum or pus producing the change. That which brain substance undergoes is either of this kind, produced by insufficient supply of blood, or by fatty degeneration, and these

three varieties are known respectively as the red, white, and yellow ramollisement. 3. Contraction is most generally the effect of organised lymph, which, when formed in the sub-mucous tissue of canals, produces stricture; and in front of this narrowing the calibre becomes diminished in proportion to the decreased bulk of the matters which pass through it. 4. Dilatation follows the accumulation of contents in hollow organs which become too weak to expel them, and is exemplified in the heart, air-cells, colon, &c. 5, 6, 7. Obstruction, compression, and displacement are mechanical alterations which often result from aneurismal or other tu

Idiopathic Emphysema.

mours, or from great effusions. A well known example, pleural effusion, will so obstruct and compress the lung

as to deprive it of all air, and will displace the heart far from its normal site. 8. Rupture of the heart may result from excessive action when disease has softened its texture.

I have been tempted to introduce the foregoing illustration of a case, I believe unique-namely, one of general emphysema quite idiopathic-as the child (a patient, some years ago, in the South Eastern Hospital) never received any mechanical injury, or was not the subject of any septic disease.

QUESTIONS FOR EXAMINATION.

JUNIOR.

1. How does a tumour differ from an hypertrophy ? Mention the two great divisions of them.

2. Mention some contents of proliferous cysts.

3. What benign tumours are hardest after bone? Describe the obvious characters on section.

4. What tissues may be the seat of vascular tumours? Have they been found as outgrowths on a naturally erectile tissue?

5. Mention the frequent seats and microscopical characters of epithelioma.

6. What are the kinds of cancer? Contrast them, and state the most frequent seats of each.

7. Mention a few examples of physical alterations produced in tissues by perverted nutrition.

SENIOR.

1. Enumerate the sub-varieties of cystic and solid tumours. 2. Explain the opinions entertained of the nature of "encysted hydrocele" of the testis, especially that of Müller.

3. Under what heads as tumours would you place the common nasal polypus, and the pendulous tumour of O'Ferrall?

4. Mention a few adenoid tumours. Who described the most frequent of them first?

5. State the points of resemblance and of difference between recurrent fibroid tumours and cancer.

6. Is it important to ascertain the position of orbital cancerous tumours with respect to the tunica vaginalis oculi?

7. What are the abnormal states of the blood in cancer?

ABNORMAL INNERVATION.

THE great subject of the lesions of innervation is so inseparably connected with special pathology, that I must content myself with giving definitions merely of the more important varieties of nervous disorders. Detailed descriptions seem the less necessary as the abnormal nutritive changes we have been just discussing constitute the essence of many lesions heretofore considered peculiarly nervous: for example, Brown-Sequard has shown that all forms of paraplegia are either due to an increased or to a decreased quantity of blood in the spinal cord. Our knowledge of the pathology of innervation is not at all commensurate with that of the function of nutrition, but recent advances in the physiology of this system have been already followed by corresponding additions to our knowledge of its morbid changes. When the student has, therefore, mastered the subject of healthy innervation, he will be enabled to study with advantage its diseases, which are fully treated of in the masterly works of Hughes Bennett, Brown-Sequard, Russell Reynolds, and especially in Romberg's monograph, translated for the Sydenham Society by Dr. Sieveking.

Cerebral diseases constitute the first class of the abnormal states of the nervous centres, and they have their seat in the interior or in the convolutions of the hemispheres. The principal varieties are as follows: 1. INSANITY, or unsoundness of mind, which has been subdivided as follows by Tuke and Bucknill:

Idiocy (including imbecility and cretinism).

2. UNCONSCIOUSNESS, which, if characterised by prolonged somnolency, is termed "trance," or, if associated with mental excitement, 66 ecstasy." 3. APOPLEXY,

which may be defined as sudden loss of mental, sensorial, and motorial power dependent on cerebral cause. According to its anatomical nature, apoplexy is either simple or congestive, sanguineous or serous; and according to symptoms, Abercrombie divided the disease into primary, non-primary, and paralytic-which latter is popularly known as a "paralytic stroke." Syncope and apnoea present the same nervous conditions as apoplexy, but the heart and lungs are respectively the seats of these pathological states. Narcotic poisons generated in the blood, as urea; or introduced from without, as opium, alcohol, or chloroform-and those agents which produce the condition surgically termed "compression," depressed bone, or effused blood, serum or pus, for examples-give rise to coma, which is not always readily distinguishable from apoplexy. Saltatory movements, tremors, perverted ideas, delirium, somnambulism, prostration by fright or surprise, vertigo, head-ache, feelings of lightness or heaviness, &c., are nervous symptoms which cannot be connected with any positive pathological state.

II. Spinal diseases, in which both the cord and its intra-cranial prolongation are engaged, their functions being either decreased, increased, or perverted. 1. IRRITATION-indicated by hyperæsthesia, or increased sensibility or pressure along the vertebral column, "often associated with a variety of neuralgic, convulsive, spasmodic, or paralytic disorders, affecting, in different cases, all the organs and viscera of the body, and so giving rise to an endless number of morbid states" (Bennett). 2. HrsTERIA-a combination of mental, sensorial, or motorial symptoms, occurring paroxysmally, imitating almost every known disease, and which is probably connected with uterine malady. 3. CHOREA-irregular clonic convulsions