Page:EB1911 - Volume 05.djvu/188

 crossed latticed lines drawn across a legal document to annul it, hence to delete or destroy.

 CANCELLI (plural of Lat. cancellus, dim. of cancer, a crossing bar), in architecture, the term given to barriers which correspond to the modern balustrade or railing, especially the screen dividing the body of a church from the part occupied by the ministers; hence “” (q.v.). By the Romans cancelli were similarly employed to divide off portions of the courts of law (cf. the English “bar”).

 CANCER, LUIS (d. 1549), Spanish missionary to Central America, was born at Barbastro near Saragossa. After working for some time in Dominica and Haiti, he crossed to the mainland, where he had great success in pacifying the Indians whom more violent methods had failed to subdue. He upheld the cause of the natives at an ecclesiastical assembly held in Mexico in 1546, and three years later, on the 26th of June, met his death at their hands on the west coast of Florida.

 CANCER (“”), in astronomy, the fourth sign of the zodiac, denoted by the symbol ♋︎. Its name may be possibly derived from the fact that when the sun arrives at this part of the ecliptic it apparently retraces its path, resembling in some manner the sidelong motion of a crab. It is also a constellation, mentioned by Eudoxus (4th century ) and Aratus (3rd century ); Ptolemy catalogued 13 stars in it, Tycho Brahe 15 and Hevelius 29. Its most interesting objects are: a large loose cluster of stars, known as Praesepe or the Beehive, visible as a nebulous patch to the naked eye, and Cancri, a remarkable multiple star, composed of two stars, of magnitudes 5 and 5.7, revolving about each other in 60 years, and a third star of magnitude 5.5 which revolves about these two in an opposite direction in a period of 17½ years; from irregularities in the motion of this star, it is supposed to be a satellite of an invisible body which itself revolves about the two stars previously mentioned, in a period of 600 to 700 years.

 CANCER, or (from Lat. cancer, Gr. , an eating ulcer), the name given to a class of morbid growths or tumours which occur in man, and also in most or all vertebrate animals. The term “malignant disease” is commonly used as synonymous with “cancer.” For the general pathology, &c., of tumours see.

Cancer exists in various forms, which, although differing from each other in many points, have yet certain common characters to which they owe their special significance.

1. In structure such growths are composed of nucleated cells and free nuclei together with a milky fluid called cancer juice, all contained within a more or less dense fibrous stroma or framework.

2. They have no well-defined limits, and they involve all textures in their vicinity, while they also tend to spread by the lymphatics and veins, and to cause similar growths in distant parts or organs called “secondary cancerous growths.”

3. They are undergoing constant increase, and their progress is usually rapid.

4. Pain is a frequent symptom. When present it is generally of a severe and agonizing character, and together with the local effects of the disease and the resulting condition of ill health or “cachexia,” hastens the fatal termination to which all cancerous growths tend.

5. When such growths are removed by the surgeon they are apt to return either at the same or at some other part.

The chief varieties of cancer are Scirrhus or hard cancer, Encephaloid or soft cancer and Epithelial cancer.

Scirrhus is remarkable for its hardness, which is due to the large amount of its fibrous, and relatively small proportion of its cell elements. It is of comparatively slow growth, but it tends to spread and to ulcerate. Its most common seat by far is the female breast, though it sometimes affects internal organs.

Encephaloid is in structure the reverse of the last, its softness depending on the preponderance of its cell over its fibrous elements. Its appearance and consistence resemble brain substance (hence its name), and it is of such rapid growth as to have given rise to its being occasionally termed acute cancer. Its most frequent seats are internal organs or the limbs. Ulceration and haemorrhage are common accompaniments of this form of cancer.

Epithelial cancer is largely composed of cells resembling the natural epithelium of the body. It occurs most frequently in those parts provided with epithelium, such as the skin and mucous membranes, or where those adjoin, as in the lips. This form of cancer does not spread so rapidly nor produce secondary growths in other organs to the same extent as the two other varieties, but it tends equally with them to involve the neighbouring lymphatic glands, and to recur after removal.

Cancer affects all parts of the body, but is much more frequent in some tissues than in others. According to recent statistics prepared by the registrar-general for England and Wales (sixty-seventh annual report) the most frequent seats are, in numerical order, as follows:—males—stomach, liver, rectum, intestines, aesophagus, tongue; females—uterus, breast, stomach, liver, intestines, rectum. Other statistics give similar, though not identical results. It may be said, broadly, that the most frequent seats are the female sexual organs and after them the digestive tract in both sexes. In children, in whom cancer is rare, the most frequent seats appear to be—under five, the kidneys and supra-renal bodies; five to ten, the brain; ten to twenty, the arm and leg bones.

Cancer tends to advance steadily to a fatal termination, but its duration varies in different cases according to the part affected and according to the variety of the disease. Soft cancer affecting important organs of the body often proves fatal in a few months, while, on the other hand, cases of hard or epithelial cancer may sometimes last for several years; but no precise limit can be assigned for any form of the disease. In some rare instances growths exhibiting all the signs of cancer may exist for a great length of time without making any progress, and may even dwindle and disappear altogether. This is called “spontaneous cure.”

Cancer has been the subject of observation from time immemorial, and of the most elaborate investigation by innumerable workers in recent years; but the problems of its origin and character have hitherto baffled inquiry. Modern scientific study of them may be said to have begun with J. Müller’s microscopic work in the structure of cancerous tissue early in the 19th century. A great impetus to this line of investigation was given by the cellular theory of R. Virchow and the pathological researches of Sir J. Paget, and general attention was directed to the microscopic examination of the cells of which cancer is composed. This led to a classification, on which much reliance was once placed, of different kinds of cancer, based on the character of the cells, and particularly to a distinction between carcinoma, in which the cells are of the epithelial type, and sarcoma, in which they are of the connective tissue type. The distinction, though still maintained, has proved barren; it never had any real significance, either clinical or pathological, and the tendency in recent research is to ignore it. The increased knowledge gained in numerous other branches of biological science has also been brought to bear on the problem of cancer and has led to a number of theories; and at the same time the apparently increasing prevalence of the disease recorded by the vital statistics of many countries has drawn more and more public attention to it. Two results have followed. One is the establishment of special endowed institutions devoted to cancer research; the other is the publication and discussion of innumerable theories and proposed methods of treatment. Popular interest has been constantly fanned by the announcement of some pretended discovery or cure, in which the public is invited to place its trust. Such announcements have no scientific value whatever. In the rare cases in which they are not pure quackery, they are always premature and based on inadequate data.

Organized cancer research stands on a different footing. It may be regarded as the revival at the end of the 19th century of what was unsuccessfully attempted at the beginning. As early as 1792, at the suggestion of Mr. John Howard, surgeon, a ward was opened at the Middlesex hospital in London for