the exercise has been for several years very generally abandoned.

In the cases in which it is referred to in this essay, there has existed, for the most part, an insufficient adducting energy, but no very considerable degree of insufficiency such as would be shown by the dot and line test of Von Graefe.

The distinction between the two forms of insufficiency will be dwelt upon more at length in its appropriate place, and it remains only to say here that such exercise in suitable cases proves of infinite benefit. Hereafter the term "insufficient adducting power" will be used to describe the condition amenable to such exercises, while the term "insufficiency of the internal or external recti muscles of a stated number of degrees" will express the condition commonly described as insufficiency of the recti muscles.

The following case illustrates a very frequent cause of headache and of other nervous symptoms:

A young gentleman had for several years suffered almost continuous headache during waking hours. His plans of life had been seriously modified by the constant torture he suffered, and he was often in charge of a physician.

Deficient energy of the ciliary muscles in the act of accommodation was supposed to be the cause of his trouble. Tablets containing small quantities of extract of Calabar bean were placed upon the eyes daily for a few days in succession, followed by the occasional but less frequent use of the same agent for two weeks. At the end of that time he was greatly

improved, and in a month quite well of his headaches. Four years have passed with no serious return of his old complaint, and a threatened attack can be averted by a single instillation of a solution of eserine into the eyes.

Severe and long-continued headaches are sometimes accompanied by excessive symptoms of exhaustion, coldness of the extremities, and loss of muscular elasticity.

Annie W., age ten years, was brought for examination in September, 1880. She had been always subject to severe headaches, located in the temples and back of the head. Although rarely free from suffering, her pains are greater if she attempts to look at books. She is very pale and thin; walks feebly, and seems quite exhausted with very moderate exercise. The facial muscles are so little active that she seems expressionless. Her speech lacks energy, and in all respects she seems to be in a state of great nervous exhaustion.

There was found in this case marked insufficiency of the external recti muscles and very slight adductive power when accommodation was relaxed.

After increasing the adducting power by exercise, partial tenotomy of the internal rectus was performed under the influence of chloroform.

The child commenced very soon to gain strength and elasticity; expression came to the face and vigor to the limbs; the headaches ceased and mental energy followed. She has continued well during the three

years, and is now advanced in her studies beyond most of her companions of the same age.

The two portraits of Plate I, reproduced from photographs, represent a child ten years of age, who from infancy had been the victim of headaches. She was feeble, always tired, and rarely free from pain. Attempts to send her to school had proved unsuccessful, for she no sooner commenced attendance than she became prostrated. She had insufficiency of the externi, and operations for its relief was made, upon one eye June 8, 1883, and upon the other June 12th. It is needless to tell one who examines these two pictures that the change was marvelous. The weary, heavy, discouraged aspect of the child as shown by the portrait of June 8th is in remarkable contrast with that of June 20th, where vivacity and courage are embodied in her expression. The child returned home to enter school, where she has done excellent work.

In the cases above cited, headaches have been relieved by the removal of irritation induced by— 1. Hypermetropia, with insufficiency of the external recti; 2. Astigmatism, with enfeebled adducting force; 3. Enfeebled energy of the muscles of accommodation; and, 4. Insufficiency of the external recti muscles uncomplicated with any very important refractive

error.

It will thus appear that these various conditions of refractive and muscular anomalies may act as disposing causes of headaches, and that the removal of the