When aneurysm exists, the middle coat of the artery is atrophied and often wanting over a part of the distended vessel. The inner coat sometimes shares the same fate. Rupture of the aneurysm is a result always to be apprehended. To avert this accident an increase of blood pressure must be prevented. "When recovery takes place, it is effected by the thickening and strengthening of the wall of the aneurysm by the formation within it of a fibrinous coagulum that may ultimately become organized tissue. Diet has been regulated with the hope that coagulation of the blood within the aneurysm would in that way be promoted, but it is doubtful whether permanent good results can thus be effected.

The quantity of fluid imbibed should be restricted, so that the aneurysm will not be distended by it. Only easily digested and moderate quantities of food should be eaten. If indigestion exists, it must be corrected, and constipation must be relieved or averted. If the stomach and bowels can do their work well, a varied diet may be prescribed; but care must be taken to limit the quantity eaten. Indigestion and constipation will, in a few cases, necessitate special diets. If atheromatous lesions and arteriosclerosis have led to the production of aneurysm, nitrogenous foods must be used sparingly. Milk is the best basis of a diet, but it cannot be used without restrictions, or the arteries will be overfilled with fluid. It may be supplemented with cereals, breads, vegetables, fruits, and very limited quantities of egg, fish, oysters, and the breast of chicken.

It is interesting to recall the regimen formerly prescribed for aortic and other aneurysms that could not be treated surgically. The treatment commonly called Valsalva's, as reported by Morgagni, was to "detain the patient in bed for forty days, and during this period to subject him to repeated bleedings, while at the same time the diet and drink were carefully ordered, so that the daily allowance, administered in three or four meals, should never be such as to fill up the blood-vessels. He made it a custom to diminish the quantity of meat and drink more and more every day till it was brought down to half a pound of pudding in the morning, and in the evening half that quantity, and nothing else except water, and this also within a certain weight. After having sufficiently reduced the patient by this method, so that, by reason of weakness, he could scarcely raise his hand from the bed in which he lay, the quantity of aliment was increased again by degrees until the necessary strength returned so as to allow of raising up."

It is true that this regimen, or one approaching it, though not so severe, often has caused pain to lessen or to disappear, the aneurysm to become smaller and to pulsate less, but most patients have regarded the cure as worse than the disease. Tufnell devised a modification of Valsalva's regimen, which was often used. He did not bleed. He required rest in bed for eight or ten weeks at least. For breakfast he prescribed two ounces of white bread and butter, with two ounces of cocoa or milk;for dinner three ounces of boiled or broiled meat, with three ounces of potatoes or bread and four ounces of water or light claret; for supper, two ounces of bread and butter and two ounces of milk or tea, making in the aggregate ten ounces of solid and eight of fluid food in twenty-four hours, "and no more."

So restricted a diet is no longer believed essential to good treatment. An abstemious but nutritious one is. Rest in bed, or in mild cases the gentlest exercise, must be insisted upon. The iodids are almost universally relied upon to-day. Surgical treatment is inapplicable to aortic aneurysm, though some good results have followed electrolysis with the introduction of wire.

During the last few years subcutaneous or intravenous injections of gelatin have been used with success for they promote blood-clotting. Of course, the strictest care must be taken to prevent sepsis. A sterilized solution of 1 or 2 per cent, of gelatin in physiologic salt solution is the strength usually employed. As much as 5 per cent, has been used. Subcutane-ously, from four to eight ounces are injected at one time. The aneurysm pulsates less violently or ceases to do so altogether, and gradually contracts. Pain and pressure symptoms lessen or disappear. Failures follow this as they do other modes of treatment, but a sufficient number of successes have followed it to make it worth trying. In some cases the internal administration of gelatin has been tried, and good results have been claimed for it.