the anatomical changes in the tissues following the blocking of the capillaries.

Since a falling blood-pressure is the outstanding symptom of shock, the proof demanded (1) that fat-globules should be injected into the vessels; (2) that the blood-pressure should be measured; (3) that the blood-pressure should fall gradually as it does in shock; (4) that the other symptoms seen in wounded soldiers should be accurately reproduced in the injected animal. These other symptoms are a feeble and rapid heart-beat, frequent and shallow respiration, pallor, low temperature, diminished sensibility, and apparent unconsciousness.

On February 2, 1917, the crucial experiment was made. An instrument for recording the blood-pressure in the carotid artery of an anesthetized cat was arranged to write its record on a moving surface of smoked paper. When the normal pressure was in record, a little less than a teaspoonful of olive oil was injected into the jugular vein. Thereupon the blood-pressure began to fall, and the animal soon showed all the phenomena of shock observed in the wounded soldier.

My attention was then directed to the discovery of a new remedy. Following the plugging of the capillaries by fat, the arteries and the heart are partially emptied; and the blood collects in the veins, especially in the large and numerous abdominal veins. In fact, the patient may be said to bleed to death in his own veins, since the quantity of blood left in the arteries does not suffice for the nutrition of the cells of the brain and other organs.

My first experiments were directed to altering the physical condition of the fat which had plugged the capillaries, so that it might pass through these narrow straits and free the channels for the nourishing blood. These experiments have not yet succeeded. VOL. 121 - NO. 1

Even if they had, they might not have proved of value in established shock. The plugging of the blood-vessels undoubtedly sets in train the falling blood-pressure and other phenomena of shock. But the condition once established, the patient cannot be saved unless the excess of blood in the veins is brought back into the arteries. If that can be done, experience shows that the patient will usually recover. Either the stopped capillaries free themselves, or other capillaries take up the duties of their injured neighbors. The practical point is to draw the blood from the engorged abdominal veins into the chest, where it shall fill the half-emptied heart and permit that faithful organ to fill the capillaries. To that end, I proposed the respiratory pump.

The air is drawn into the chest chiefly by the diaphragm, a large flat muscle which separates the chest from the abdomen. When the diaphragm descends in inspiration, the cavity of the chest is enlarged. If a squeezed rubber ball is allowed to expand under water, the surrounding fluid enters the ball. So, when the cavity of the chest. is expanded, surrounding fluids enter the chest; the air is sucked in through the trachea and blood is sucked in through the veins. The blood is sucked into the chest with considerable force. If the normal quiet contraction of the diaphragm so aids the entrance of blood into the chest, its powerful contraction will aid still more. Powerful and frequent contractions are within our command. We have but to increase the carbon dioxide in the inspired air to call forth deep and rapid respiration. The necessary amount of carbon dioxide is not injurious.

These facts concerning the respiration and its influence on the circulation were known to every physiologist. My contribution consisted in applying them to shock. My remedy therefore

was to increase greatly the action of the respiratory pump by having the patient breathe an atmosphere rich in carbon dioxide. Meanwhile he was to be placed in an inclined position, with the abdominal vessels higher than the heart, so as to favor by gravity the flow of blood from the abdomen into the chest. In my animals with shock, this increased respiration raised the blood-pressure sufficiently to warrant the hope that valuable results would follow the treatment when applied to wounded men. Upon this hope the

Rockefeller Institute for Medical Research had sent me again to France.

III

Forty-eight hours after my strategic defeat in the restaurant on rue Cambon, I was walking with Major Cunder fire over the gently rising terrain leading to the Massif de Moronvillers. It was my purpose to try the new remedy, and to measure the blood-pressure in normal and wounded soldiers during a sharp offensive.

The meadow larks were singing. Even the major sang. And the air above was filled with the song of shells. The several harmonies were stratified. From the lush grass of early spring rose small chirpings and hummings; then came the major, having as it were a layer all to himself; then the meadow larks, numerous and undismayed; still higher were heard the hissing three-inch shells; and up in the blue the mournful droning of the great projectiles.

'If you search these fields,' remarked the major, you will find in every square metre at least one piece of shell.' It was true. I looked through fifty square yards or more, and in each was at least one fragment of steel.

'It is forbidden to walk in these fields,' said the major. 'Perhaps we had better get into the trench.'

I took a last general view of our position. Behind us, the German fire was painting with dark smudges the village through which we had just come. Far across the plain too far to see - lay Châlons-sur-Marne. To the left, miles away, was the Montagne de Rheims, bearing on its fruitful slopes the celebrated vineyards of Champagne. In front rose the Massif de Moronvillers, crowned with its hills of fame - Mont Cornillet, Mont Blond, Mont Haut, the Casque, and the Téton. Their de cent garments of green were torn away. Naked they lay. On their livid slopes the trenches crawled like great white worms. Streaks of flame and sudden bursts of black smoke marked the constant fall of German shells. Thrown high in the air, the pale chalk-dust drifted with the acrid fumes among the riven pines.

We entered the communication trench, a deep and narrow passage, writhing through the chalk like a snake in pain. When we came to the lines, the trench sank into a gallery. Dug by the Boche, it now served his enemy. The gallery was seven feet wide. At the farther end were four or five wooden bunks in which the Staff slept. In the middle were two tables. One supported a pair of typewriters, industriously nibbling at a mound of papers, under a small acetylene flare. On the other table was a row of aluminium porringers, salt, pepper, war-bread, and a small bowl of sugar.

We lunched. The colonel was an energetic and smiling veteran of forty-five, hard and fit. His face glowed like a dull red coal in the shadows of the cave. Six galons were upon his sleeve, one for each of his six wounds.

The food was simple but sufficient. The ritual of the déjeuner was scrupulously observed. It was as if a gentleman handed a poor relation into a carriage. The colonel and I sat side by

side. Conversation flowed like milk in the Land of Canaan. The subject indeed was cows. It appeared that the regiment possessed a cow. This was unusual. The Marseillaise, the Ten Commandments, and Our Cow seemed on the same plane. As a breeder of Guernseys, these discerning people moved my heart. We were friends.

When night came, I took off my boots, belt, and helmet, and slept on a stretcher. At half-past three, an imperative hand shook my shoulder. 'Gas! Be quick!' I seized the mask, which changes the man of peace into the ghoul of war. I pulled on my boots and put on my helmet. We ventured out. On the crest of the Massif, the stars of God paled before the starshells of the Huns. It was the hour before dawn. A lively bombardment was in play. Cocks crew, still faithful to their conviction that, but for them, the sun would not rise. I reflected that, but for us and our seven million comrades, the sun might set never to rise again. We sniffed the cool damp air for the odor of chocolate which betrays the creeping death. But the gas was not for us. Far down on the horizon hung the gibbous moon. Across her chill and disapproving face passed black slim shapes incredibly swift eight-inch shells plunging to their rending crash.

Back in Division Headquarters, General F had at first suggested that I should be stationed in the celebrated tunnel on Mont Cornillet, taken from the enemy four days before my arrival. The tunnel was dug deep in the chalk. It was very large-large enough to hold a dressing-station and six hundred German reserves. It had a big ventilating shaft. By a strange chance, a sixteen-inch French shell passed through this ventilating shaft and exploded among the Boches. All were instantly destroyed. Compara

tively few showed a wound - they were killed by the gas-pressure and the fumes.

The commotion made by an exploding shell is extraordinary. I have often felt the strong push of hot gas as if I had been struck by a flying cushion. Among my friends in Paris was a French aviator who had begun the war as an infantryman. His platoon held a first-line trench. A Busy Bertha fell among them. Some were killed by flying fragments, others by the concussion. A comrade of my friend was pushed by the blast against the hard clay wall of the trench, with such force that both the skull and the chest were crushed. They were visibly flattened.

The incident of the tunnel was certainly remarkable. But a still stranger accident had befallen the French a few days before my arrival. The regiment brigaded with the 365th had its headquarters in a gallery thirty feet below the surface. It was apparently quite safe. Two large shells fell on that spot. The first made a crater fifteen feet deep directly over the gallery. The second fell exactly in the bottom of this crater, broke into the refuge, and killed the colonel and the officers with him.

1 May 23.

It was fortunate for me that I was not put in the Mont Cornillet tunnel, but in a cave on Mont Blond; had I been, I should have missed a wonderful experience- the battle on the crest.

I was conducted to my new home the morning of the gas alarm. My cave was on the slope of Mont Blond, a little more than a thousand feet from the crest. Perhaps three hundred feet below us the slope ended in a path, and beyond rose another low hill, near the top of which was the regimental headquarters I had just left. The cave

1 The remainder of this paper is copied verbatim from letters written on the spot.

had been dug by the Germans. The roof was almost flush with the surface. There was nothing to mark the spot, except that the universal wrack was there accentuated.

Battered tins, coils of barbed wire, scraps of leather, a broken stove upside down, rusted clips of cartridges, burlap sacks mired with clay, decayed bandages, a hopeless old rifle, intrenching tools, discarded helmets punched with shell-holes through which the brains of the owner had probably oozed, old shoes, battered shell-cases, and a trench torpedo lay about, halfburied in the dirt thrown out of the

craters.

Five or six steps screened with dead branches led into the cave. It was about six feet deep. The roof was supported by projecting beams. The sides were clumsily boarded. Here and there were openings dug farther into the earth and provided with shelves which were covered with accoutrements, flat circular wine-flasks in canvas, tin cups, musettes lumpy with a miscellaneous kit, packages of food, bundles of dressings all in great confusion and all thickly smeared with dirt. The furniture consisted of a couple of benches and a greasy table. The table stood against a wall. On one end were the surgical tools, bandages, packages of gauze, et cetera. On the other, three or four small cooking utensils and an alcohol lamp.

The room was full of men: three surgeons and eight or nine brancardiers in a space ten by twelve feet. A ladder led into a lower cave, six by seven feet, the floor of which was fifteen feet below the surface. Here were bunks of unplaned boards. Twenty feet away was another shelter, an overflow, still more primitive.

In our own cave dinner was being prepared. Dinner was served here at noon, for greater convenience. Out

side, the Boches were very active. The slope was being searched with shells in the thorough German way. The living heeded this mortal rain no more than the stoic dead, who lay about us, beneath their crosses two rough boards in the form the Prince of Peace had sanctified.

Through the hot fire appeared the major, very brisk, clean-shaven, immaculately clothed, plump and smiling. Under his arm was a long bottle, converted to the ways of innocence. The major made a gay salute. "The colonel presents his compliments and hopes you will accept a litre of fresh milk.' Delightful colonel! O gentle cow, all red and white! We drank an English toast with gusto: 'To hell with the Huns!' Everybody laughed. The bearded poilu detailed as chef plunged his great spoon into the tub of solid alcohol at his feet and fetched up a huge lump to feed the flame under our crackling meat, as who should say, "This for the Boches!'

Dinner was served. The few who could find a place sat down. The rest stood, each with his porringer. We had hors d'œuvres, consisting of sardines and sliced onion with bread and butter, omelette, beef with sauce tartare, potato salad, oranges, and cakes. Jokes flew about, but they were harmless jokes. Neither then nor at any other time did I hear from French soldiers the coarse obscenity which too often mars the fighting men of other nations.

In the afternoon, I went with an officier de santé into the advanced trenches. But trenches is not the correct term. The Germans had been forced back and off the whole extent of the Massif de Moronvillers, until they had lost all the crest but the position immediately above our cave. The French first line lay beyond the old German trenches, in a series of shell

holes connected by hasty ditches. It was very warm here; in some places there were more dead than living. The commandant of this section complained to my officier de santé. The dead were not removed quickly enough. He could sentir them. They had begun to rot. We returned safely to the cave. As we stood at the entrance, a German plane passed high over us. We dived for shelter. None too soon. A moment later three shells fell, in quick succession, close to our post. These caves are not proof against direct hits, though safe enough from fragments. Two days after my departure, a shell entered the poste de secours next to ours, killing the two surgeons and five brancardiers. There are hours when the fire is light, though it never ceases. Again,

it will swell almost to drum-fire. It is not safe to go more than a few feet from the cave, lest you be caught in one of these sudden storms. When it is possible, I sit in the mild May sunshine on a burlap at the top of our steps. The probable course of a shell can be told from the sound. When the hiss crescendo seems to be coming straight for you, a swift plunge is in order.

A sharp watch for planes is necessary. In my first summer, at Nieuport and elsewhere, the planes did not usually attack small groups of soldiers. But here, at the Massif de Moronvillers, they have a nasty habit of dropping suddenly from the sky, spitting steel from their mitrailleuses.

the

The gas-shells are very numerous and very deadly. My colonel one who sent the milk- was laid up three weeks from gas that had crept through a very small opening where, because of his high cheek-bones, the edge of the mask failed to press firmly against his face. Our masks contain several layers of gauze saturated with different chemicals to neutralize the various fumes.

When darkness came we prepared for bed. At half-past eight my orderly saluted. He had been before the war a teacher of Latin in the High School at Lille. His wife and two children were refugees. The wife had tuberculosis from her hardships. He informed me in his precise French that my couch was ready. I climbed down the ladder to the lower cave, backwards and bent double, since the entrance was a low slanting shaft. Gérard pulled off my great trench-boots, hung up my belt and helmet, and folded my raincoat for a pillow. I lay down on the bare planks. He placed my heavy overcoat over me and wished me pleasant dreams. I told him that in my youth I had often been put to sleep by a teacher of Latin, but I had never before been put to bed by

one.

During the night, the Boches bombarded points below us with gas-shells.

(Dr. Porter's final paper, The Clue,' will appear in the February number.— THE EDITORS.)