lau, comprising 8574 scholars. Among the city schools, twenty were primary and the remainder schools of higher grade, including gymnasia or colleges. Of the 10,060 pupils examined by M. Cohn, 1730 were found "ametropic," a general term given to cases of defective vision from defective adjustment, including all cases arising from irregularity of refraction in the transparent media of the globe of the eye; when the refraction is in excess, it is called one of "myopia;" when the refraction is deficient, it is called "hypermetropia" and when the refracted rays are very irregularly transmitted to the retina or screen for receiving the image of the object looked at, the condition. is called one of astigmatism.

The table stands thus: Of the 10,060 cases examined 8.330 or 83 per cent. had sound normal eyes with perfect sight; 1.330 or 13 per cent. were found with errors in refraction; 296 or 3 per cent., embracing all other diseases of the eyes. This table shows that among school children there are more diseases in refraction than of all other diseases of the eye put together.

Among the 1330 cases of defective vision, 1072 were myopic or near-sighted; 239 were hypermetropic or oversighted, and only 23 were astigmatic, or cases in which there was no perfect focus found upon the retina, either for long or short distance.

M. Cohn deduces the following as the result of his extended observation among a large number of children. 1. That cases of myopia can be found in every school. 2. That the number of these cases will continually vary, depending upon the grade of the school.

3. That but few cases are met with in country schools, only 1.4 per cent.

4. That, in the same grade of school, myopia will be found eight times more frequently in city schools-11.4 per cent.

5. In primary schools of cities there are four or five times more cases of myopia than in rural schools-6.7 against 1.4 per cent.

6. That superior schools for girls exhibit more cases than in primary schools-7.7 against 6.7 per cent.

7. In city schools the frequency of myopia bears a fixed relation to the grade of the school-primary, 6.7 per cent.; medium schools, 10.3 per cent.; normal schools, 19.7 per cent.; gymnasia, 26.2 per cent.

8. In country schools, as in those of cities, the proportion of myopics vary according to the status of the school, but never more than 2.4 per cent.-the lowest age being 0.8, the highest 3.2 per cent.

per cent

9. In a given number of the higher schools the per centage of myopia would differ but little in the individual schools. Of the one hundred and sixty-six classes in the thirty-three schools, the eleven lowest classes contained no myopics. In the rural schools the pupils were arranged in three classes, and defective vision was found among them in the following proportions: The third, or lowest class, gave 1.4 per cent. myopic cases; the second classes, 1.5 per cent.; the first, or most advanced classes, 2.6 per cent. of myopia. A similar organization among the city primary schools gave, for the third, or lowest classes, 3.5 per cent. of near-sighted pupils; in the second order, 9.8 per cent., and in the first, or highest classes, 9.7 per cent. In the normal schools, commencing with the lowest form, we have the following per centage of myopics among the pupils: 9.6 per cent., 16.7 per cent., 19.2 per cent., 25.1 per cent., 26.4 per cent., 44 per cent., and lastly, in the gymnasia, or highest schools, the classes in similar order were found thus: 12.5 per cent., 18.2 per cent., 23.7 per cent., 31 per cent., 55.8 per cent. In the highest branches of study, more than one-half of the students were near-sighted, and, in whatever school selected,

the higher classes always exhibited an increased myopia over the per centage found in the lower classes.

The examination of the eyes of these many scholars also showed that the degree of myopia was always in relation with its frequency. With advancing age and higher studies, requiring more continued application, there was always a steady advance in the degree of defective refraction. In the lowest classes, with young children, 1-35 marked the degree of myopia; in the highest classes, among the most advanced pupils, it had increased to 1-7, which would require very strong concave glasses to remedy the defect of refraction. Of the 1072 cases of myopia, only twenty-eight could be traced to hereditary causes, a proof that short-sightedness is most frequently an acquired condition, an accompaniment and product of education.

M. Cohn traces its development and progress to one of three causes :

1. Defective construction of benches in schools.

2. Defective light in school-rooms.

3. Improper use of too weak or too strong glasses by pupils.

Upon careful examination of the school-rooms, Dr. Cohn found the benches and desks very defective as to their arrangement, position, hight and inclination, and not suited to the hight of those who occupy them. On this account the pupils were compelled to keep the head bent in a forced position, which impeded the returning venous circulation, and produced, consequently, choroidal congestions. Also, the near position of the book upon the desk necessitated exaggerated efforts of accommodation, with excessive pressure upon the globe of the eye. These two effects of a vicious and forced attitude sufficed to produce elongation of the globe of the eye, and consequently myopia.

In investigating the second category of causes, the author established by his observations that where schools were located in narrow streets, and surrounded by lofty houses-conditions in which the school-rooms were necessarily dark-the per centage of myopic cases was always found augmented. Among the twenty primary schools of Breslau, some were located on broad streets in the new quarter, whilst others were situated in the dark and narrow lanes of the old town. Among the first of this class of schools the per centage of myopia varied between 1.8 per cent. and 6.6 per cent.; in the second class, of dark schools, the percentage varied from 7.4 per cent. to 15 per cent., clearly exhibiting the effects of bad light, and indicating the necessity for selecting school sites with judgment.

As to the third cause, the injudicious selection of glasses, Dr. Cohn found among his entire number of pupils 107 who were wearing glasses. Ninety-nine of these had selected the spectacles for themselves, and in only eight cases had they been selected by physicians. Of the entire number, twenty-six spectacles suited, the lenses neutralizing the myopia. In forty-one, the glasses were too weak, and in forty too strong.

Such are some of the causes to which Dr. Cohn attributes the great frequency of myopia in schools. He refers to the disease as one to which attention should be directed on account of its gravity. For when not cared for, the tendency of this affection is to increase with age, and may even threaten the loss of sight by the formation of a posterior staphyloma, with consecutive atrophy of the deep membranes of the eye, which are sometimes drawn into the pathological pit around the entrance of the optic

nerve.

The three practical deductions of Dr. Cohn, as preventives or prophylactics, are—

1. That the hight of school benches should always be in proportion to the hight of the children who use them. 2. That school-rooms should always be well lighted. 3. That when spectacles are required, they should always be selected by some competent physician.

ART. II. OVARIOTOMY. By J. H. THOMPSON, M.D., of Washington, D. C. Published by special request of the Medical Society of the District of Columbia, Washing, D. C.

REPORT OF THE PROCEEDINGS.

In 1868, a female patient, æt. twenty-two years, unmarried, consulted Dr. T. on account of the presence of an abdominal tumor which had existed, to her knowledge, for the last fifteen months, but of small size; three months previously, however, it had grown to such a size as to create suspicions of pregnancy among her friends. On examination, sufficient fluctuation was felt to enable the Doctor to pronounce it to be an ovarian tumor, containing fluid, and in the following month, at the request of the patient, the tumor was tapped and three quarts of fluid drawn off, consisting, to all appearances, of laudable pus. No inflammatory symptoms ensued and three days. after the operation the patient was up and about as usual, the tumor being quite small and scarcely to be detected except by careful manipulation. After a duration of three months, the patient again made her appearance, the tumor having grown to the size of a pregnant uterus of three months. It was again tapped, the instrument used being a trocar having the diameter of one-eighth of an inch, but no fluid was obtained on its withdrawal. A risk inflammation ensued, extending to the cyst wall, with circumscribed peritonitis. The patient was put under the opium treatment, and in from ten to twelve days recovered and returned home.