The Journal of San Diego History
Spring 1976, Volume 22, Number 2
James E. Moss, Editor


Images from the article


Of all the people who participated in the Sacred Expedition, Don Pedro Prat is the least understood. A well-trained doctor with awesome opportunities for new and original observations, Pedro Prat left no diary, no letters, no notes of any kind.

What we know about him, we know through others. To Father Serra, he was a celebrated surgeon. To Captain Vila, he was an annoying troublemaker. To Miguel Costansó, he was a devoted doctor and a trusted friend. To us, he is a frustrated loner who finally collapsed from sheer exhaustion.

Based partly on the few known facts and partly on subtle guesswork, this article tries to see him in perspective.

Pedro Prat heaved his medicine chest aboard and looked for a place to put it. He might as well have asked for the bone in a dog fight. Wherever he looked, men tugged, strained, grappled. The deck bristled with muskets and lances. The stalls brimmed with hardtack and bullybeef. The hold bulged with sacks of rice and the paraphernalia of an invasion. The medicine chest would have to wait.

Even without the paraphernalia of an invasion, the San Carlos was hardly a pleasure ship. Built in a hurry, she began to leak before she arrived in La Paz. Designed for a crew of 24, she wound up with 62. Rigged as a brigantine, she was a bear in a storm and a mule in a calm. Inside and out, above and below, at anchor and at sea, she was little more than a floating chicken-coop. But that did not faze the men who were now boarding her.

Least of all Dr. Prat. A graduate of the University of Salamanca, he had gone into the army because he wanted adventure. Spain being singularly free of adventure, he signed up for overseas. Soon he was in Mexico. The country was beautiful but the life was dull. It was at this point that he heard of plans for an expedition to Alta California, a mysterious land of great riches. He wrangled a transfer and arrived in La Paz late in 1768.1 The San Carlos arrived soon after. Now for the glory.

Spain could use a little glory in 1768. Ever since the great days of Columbus and Cortez, it had been downhill all the way. First, 50 years of struggle with France without tangible gain. Next, an 80-year police action in the Low Countries, again without tangible gain. Finally, in the eighteenth century, a series of exhausting wars over the territories in North America. At this very moment a new threat appeared. Foreign nations were on the prowl in the Pacific. Especially the Russians. King Carlos III issued his proclamation.

“The High Government of Spain, being informed of the repeated attempts of a foreign nation on the northern coasts of California with aims by no means favorable to the Monarchy and its interests, gives orders to the Marques de Croix, Viceroy and Captain General of New Spain, to take effective measures to guard that part of his dominions from all invasion and insult.”

Spain had made its move but not with great enthusiasm. To occupy an area larger than Spain itself, the Viceroy dispatched an expeditionary force of less than 100 soldiers under the command of a captain. Even if the natives turned out friendly, the occupiers would have their hands full. Moreover, the land was still virtually uncharted. Vizcaino’s visit in 1602 was little more than kiss and goodbye. Obviously, these new invaders would have to play it by ear.

What they lacked in numbers, they made up in zeal. Military commander was Captain Gaspár de Portolá. Religious leader was Father Junípero Serra. Expeditionary surgeon was Dr. Pedro Prat. Assembled in La Paz, these planners decided to spread the available force over five echelons: three by sea and two by land.

The San Carlos was the first to leave.2 She sailed on January 1, 1769. Six weeks later, a smaller ship, the San Antonio, took off. A third ship sailed later yet. This was the San Jose which had been designated the supply ship. She took off, returned for repairs, took off again, and disappeared at sea.

Meanwhile, the overland echelons gathered in Loreto, north of La Paz. Captain Portolá marched on March 9, and Captain Rivera y Moncada on March 24. Delayed by religious duties and by his ailing legs, Father Serra left a few days later. In spite of every effort to synchronize the arrival of the echelons, Father Serra was to arrive in San Diego a full ten weeks after the San Carlos.


The Invisible Enemy

The loading of the San Carlos was now complete. Even the medicine chest had found a little nook of its own. With the men assembled on deck, Father Serra said Mass. The Inspector-General was next. The object of the expedition, he said, was to raise the cross and seize the two major ports: San Diego and Monterey. If the natives objected, they were to be pacified by appropriate means. Peace and harmony prevailing, the ships were then to return. His Excellency said very little about the built-in dangers of the job. Adelante!

The next day the San Carlos headed out to sea. As she rounded Cabo San Lucas, Dr. Prat went over the manifest. It listed first Captain Vila with the mate and 23 sailors. Next, Lieutenant Fages and 25 soldiers, fresh from Spain. Next, Father Fernando Parron and the cartographer of the expedition, Miguel Costansó. Finally, a sprinkling of cooks and bottle washers. In this motley crew, Dr. Prat rated a little above the soldiers and a little below the lieutenant. But that was the least of his worries. His biggest worry was how to keep all these men healthy in the cramped quarters of the ship. For that, he had to be a magician.

Dr. Prat carried another manifest for the supplies on the San Jose.3 It listed 10 barrels of meat, 33 sacks of flour, 6 sacks of rice, 10 sacks of beans, 29 bushels of corn, 2 sacks of barley seed, 10 bushels of brown sugar, 1 box of coarse chocolate, 18 pounds of melon seeds, 10 pounds of watermelon seeds, 10 pounds of pumpkin seeds, an unspecified quantity of crackers, 1 box of fine chocolate, 1 barrel of California vinegar, and an unspecified quantity of lemon juice. This last entry is of great interest. It proves that Dr. Prat knew the medicinal value of lemon juice.

Trouble started almost at once. The west coast of Baja California is a nightmare for a sailor going north. Persistent head winds forced the ship to long and futile tacks. A violent storm drove her 200 leagues to sea. The cargo was in constant danger of shifting. So severe was the pounding that the water casks began to leak. Most of the men were laid up with seasickness. But seasickness was nothing compared with a far more deadly disease that was waiting in the wings. It made its entry with dramatic impact.

Only 12 days out of port, a seaman by the name of Augustin Medina broke his leg in a fall against the tiller. Dr. Prat improvised a splint and put the patient at rest. The next day, the leg had swollen to twice its size. Alarmed, Dr. Prat prescribed laudanum and henbane. The next day, the leg was as big around as a watermelon and the skin as tight as a drum. Leeches and purges were to no avail. After a few more days, the entire leg was black and blue as if it had gone through a meat grinder. Dr. Prat removed the splint. Without it, the useless and turgid extremity banged against the bulkhead with every roll of the ship. Delirious with pain, the patient begged to be put out of his misery. It was at this point that Dr. Prat woke to the chilling realization that his patient had scurvy. The fractured bone ends continually stirred up more bleeding.

For a young surgeon on his first important mission, it was a fearful situation. Hampered by the unsanitary conditions, dogged by the pleas of his patient, hounded by the specter of a lethal disease, he sensed disaster. As if to reinforce his premonitions, the storm which had raged for several days increased in intensity.

While Dr. Prat asked himself how it could be that scurvy had come so soon (normally it shows up only after many months), another patient asked for help. Fernando Alvarez, the boatswain’s second mate, complained of pain in his jaw. Dr. Prat found the gums red and swollen. The slightest touch caused bleeding. With no real prospect that he could do any good, Dr. Prat prescribed mouthwashes and wet compresses. After a few days of this treatment, the gums looked like raw beef. In addition, the teeth became loose so that the patient could no longer eat the hardtack and bullybeef. A constant ooze from the mouth so weakened the poor man that he could hardly stand. Between the stench of his fetid breath and of Medina’s half-gangrenous leg, the atmosphere in the forecastle became unbearable.


An Agonizing Impasse

Scurvy in 1769 was hardly new. It had been known since man first began to sail the seven seas. Hippocrates, 500 years before Christ, has given us a good description of the symptoms. The explorer Jacques Cartier in 1600 wrote that an infusion of Ameda leaves brings about “a miraculous cure.” But it was left to the British naval surgeon James Lind to write in 1753 that scurvy could be prevented with lemon or lime juice.4 His work was so convincing that the Admiralty ordered all ships to carry lime juice on long voyages. By 1765, scurvy had disappeared from the British navy, and British sailors had acquired the name of limeys. The name has stuck.

Although the cure of scurvy is therefore over 200 years old, the why and wherefore was to come much later. Limes and lemons contain ascorbic acid, which is the active principle of vitamin C. Ascorbic acid was first identified and synthesized in 1932. Only then did it become possible to study the mechanism of vitamin C deficiency.

Ascorbic acid in some mysterious way is essential for the integrity of the intracellular substance, the so-called collagen that holds cells together. Devoid of collagen, cells break up and die. Particularly vulnerable are the capillaries, the smallest blood vessels. Suddenly porous, these vessels leak blood into the tissues from where it escapes on to the surface.

The first symptom of scurvy is usually the scurf or scaly eruption of the legs. It is due to small hemorrhages in the hair follicles. Next, the gums become affected. The teeth drop out, and the breath becomes fetid. Eventually the patient dies of malnutrition, anemia, and internal hemorrhages.

With two desperately ill patients on his hands, Dr. Prat went to see the captain. How much longer might this journey last? The captain shrugged his shoulders. They were not even halfway.

Other patients began to crowd in on Dr. Prat. Some complained of headache, others of cramps, others of painful joints. Scurvy being a protean disease, symptoms can start anywhere. Men who were strong when they boarded the ship now could hardly remain upright on the pitching deck and in the narrow passageways. For safety’s sake, they had to bed down in the forecastle, which quickly became a grisly place. Men vomited, but there were not enough basins. Men had open sores, but there were not enough bandages. Men had dysentery, but there were not enough heads. The stench was horrible. During the day, under the blazing sun, the place became a furnace. At night, with a chill wind, it became a refrigerator. Meanwhile, the ship never ceased tossing and pitching in the heavy swells. The forecastle became a torture chamber.


Burial at Sea

The San Carlos plodded on. With the lemon juice for the expedition as far away as the moon and the stars, Dr. Prat desperately searched his medicine chest for whatever it might contain. He found wormwood for weakness, valerian for nerves, parsley for the liver, horehound for coughs, foxglove for the heart, but none of these was any good for scurvy. It now became his painful task to tell the patients that they were getting better when in fact he knew they weren’t. Taking care of the dying is the hardest thing a doctor has to do. In effect, he dies with them.

Dr. Prat was not prepared for the severity of the scurvy that struck his men. A normal person carries enough reserves of ascorbic acid to protect him for many months. We can only assume that the soldiers and sailors of the San Carlos were already vitamin-deficient at the time of boarding. In view of the restricted diets in those day[s], it is not a far-fetched assumption.

Twice more the San Carlos was buffeted by storms. Twice she had to seek out land and look for water on the arid coast. Twice she made long and needless detours, trying to follow Vizcaino’s directions. But Vizcaino had been off by as much as 100 miles. As a result, the ship wandered around off what is now Santa Barbara for days. Dr. Prat pleaded for haste. Captain Vila said that he had his orders. In the midst of the argument, Dr. Prat was called to the forecastle. Fernando Alvarez had died.

Burial was at sea. Swathed in canvas, the body was placed on a catafalque while Father Parron came forward to read the service. “Almighty God, have mercy on this poor man’s soul,” he intoned. “We, who still have the strength, pledge ourselves to the task he started. Please give us the energy.” His words brought tears to the men who well knew that they might be next.

Two days later, Dr. Prat was horrified to discover that another patient had died. Panic gripped the survivors. It was as if an incubus had descended on the ship. These men had come to fight a visible enemy. An invisible enemy was too much for them. Desperate, Dr. Prat tried to maintain their spirits. But the task was too much. His mind was beginning to slip.

Three and a half months had now gone by since the San Carlos sailed. Over a hundred days to cover eight hundred miles as the crow flies. During the final weeks of the ordeal, the forecastle overflowed and the sick had to be cared for on deck. Finally, on the morning of April 28, the lookout shouted that he could see the Coronado Islands. A great cheer went up. Vizcaino had explicitly described these islands as the key to San Diego. The entire day went by before the lookout shouted again. Land! As darkness settled, the San Carlos slowly rounded Point Loma. At last, the goal.

Words cannot describe the exultation of the men when they discovered that the San Antonio had preceded them. The San Antonio had come off better than the San Carlos. Even so, on the two vessels were only eight men capable of doing full duty. All the others were sick, many too weak to walk. The San Carlos had been en route 110 days; the San Antonio 55.


The First Steps

Dr. Prat set foot on California soil on May 1, not at what we now call Spanish landing (that piece of land did not exist in 1769) but about a mile to the west. As if to reward him, a colorful panorama stretched out before his eyes. On his left, the green ridge of Point Loma. Straight ahead, the faint outline of another bay. On his right, a hill standing guard over an oasis. Here, poplar and sycamore trees shielded a small Indian village. On the slopes of the hill, patches of wild grapes and asparagus. And in the far distance, the purple mountains, topped by a delicate frosting of white. How restful to the eye that has beheld nothing but angry water for months!

Immediately, he went in search of the berries and fruits he needed for his patients. Rosemary, sage, castilian rose and wild grape vines grew abundantly. Meanwhile, the ships advanced into the bay to be closer to fresh water. The first camp was pitched on the rising ground of what is now Laurel Street. A little later, it was shifted to the lower slopes of Presidio Hill.

On May 14, the first of the overland parties arrived. These men had suffered nothing worse than blistered feet, although at first the land route had been considered more hazardous. On July 1, the second group arrived, including Father Serra. Only Father Serra was in need of a doctor. When Dr. Prat saw the huge varicose ulcers, he was shocked. He thought that the father had cancer. Actually, a varicose ulcer is a benign condition that responds promptly to rest. But who could think of rest at that point? Not Father Serra.

Doctor and patient talked of the appalling voyage on the San Carlos. To Dr. Prat, the diagnosis was very clear. Scurvy was a deficiency disease. But Father Serra had other ideas.

“Ah! The sickness of Loanda,” he exclaimed. “I am sure it is contagious.” The sickness of Loanda was another name for scurvy.

If anyone should doubt that Dr. Prat understood the nature of scurvy, let him read Miguel Costansó’s diary of this period.

“Medicines and fresh food, most of which had been used up during the voyage, were wanting. The surgeon, Don Pedro Prat, supplied this want as far as possible with herbs he sought with much trouble and whose properties he knew. He himself needed them as much as his patients, for he was all but prostrated by the same disease. In the huts, the cold made itself severely felt at night, and heat by day—extremes which caused the sick to suffer cruelly. Every day, two or three of them died, and the whole expedition, which had been composed of more than 90 men, was reduced to only eight soldiers and as many sailors who were in condition to assist in guarding the ships, handling the launches, protecting the camp, and waiting on the sick.”

Even before Father Serra said his first Mass on July 16, he saw his expedition split. On July 9 the San Antonio sailed to get more supplies. On July 14, Captain Portola marched off for Monterey with 63 soldiers. Left behind in the bay was the San Carlos with a few sailors under Captain Vila. Left behind on the hill were Father Serra, Dr. Prat, two padres, eight soldiers, and several dozen patients. For all of them, it was a miserable existence.

Not only miserable but precarious. The Indians began to make a nuisance of themselves. They invaded the huts, disturbed the sick, stole the bedding, and made threatening gestures. One day they got into their canoes and raided the San Carlos, but they were beaten off. This experience taught the men a lesson. No longer did the padres go alone from ship to shore. They had to have an escort. It was on one of these occasions, when the little camp on Presidio Hill was left with only four soldiers, that the Indians seized their chance.

The day was August 15. While Father Serra was reading from the Scriptures and Dr. Prat was taking care of his patients, 20 yelling Indians surrounded the huts. Without warning, a volley of arrows came over. One of them struck a servant boy, who ran screaming into the arms of Father Serra. The arrow pierced the windpipe, and the boy was dead within minutes. He was the first Spaniard to die at the hands of the Indians. In the same volley, Father Vizcaino and the blacksmith were wounded.

The soldiers grabbed their weapons and returned the fire. The muskets were not of much use, but the lances were. In spite of their weakened condition, the soldiers managed to slay three Indians and wound a number of others. The invaders fled. Several days later they were back—with their wounded. Would Dr. Prat please take care of them? He did.

In this state of armed truce, life in the little stockade became a burden. Food ran low, clothes wore thin, weapons gave out. On January 24, more than six months after they left, the soldiers in search of Monterey returned. They had marched past their goal and nearly starved in the process. As the days dragged on, Father Serra and Captain Portola differed in their view of the situation. Father Serra wanted to stay at all costs. Captain Portola could see nothing but trouble ahead. In this impasse, Captain Portola set a deadline. If no help arrived by the Feast of St. Joseph (March 19), he would order evacuation. Either through Father Serra’s prayers or through sheer coincidence, the San Antonio reappeared on the very day. Now the settlers could build for the future.


A Sad End

For Dr. Prat, the year had been a shattering experience. Out of the 159 men entrusted to his care, he had seen 60 die. An educated man, he could find little companionship among the illiterate soldiers and the preoccupied fathers. The Indians had discovered alcohol and were drunk most of the time. In such surroundings, he began to go to pieces. Aware that his mind was crumbling, he asked to be relieved.

The final blow came on the voyage of the San Antonio from San Diego to Monterey. It was almost as bad as the one on the San Carlos. For six weeks, the little ship fought its way through storm after storm. Beset by physical debility and mental prostration, Dr. Prat gradually withdrew. Periods of complete silence alternated with periods of wild excitement. In fits of rage, he threatened to kill himself and others. Finally, he had to be locked up.

Viewed in the light of what we know today, Dr. Prat had schizophrenia. It is a disease marked by hallucinations, negativism, loss of contact and disintegration of the personality. The cause is unknown. The cure is also unknown, but many psychiatrists are able to bring about great improvement with large doses of vitamin B and C.5 If large doses of these vitamins can bring improvement, it is not unreasonable to suppose that lack of vitamins can cause the disease. Whether Dr. Prat’s long period of vitamin deprivation was indeed responsible for his mental collapse, nobody can say. Perhaps it was a combination of vitamin deficiency, physical hardship, and mental trauma. At any rate, we can now understand why Pedro Prat left no diary, no letters, no notes of any kind.

“I call to the attention of Your Excellency (the Viceroy) the fact that at the beginning of the expedition, a surgeon named Don Pedro Prat was assigned to it,” wrote Father Serra. “When we went to Monterey, the bark carried a large quantity of medicines so that the surgeon, reserving what was necessary for the Presidio, might distribute to the missions what he thought best.

“But we had the misfortune that no sooner was the port of Monterey found than the surgeon lost his mind. He remained one year in the Presidio but totally demented. He was afterward sent away in the bark and finally died in the hospital of the Bethlemite fathers in Guadalajara.”6

Don Pedro Prat did not live to see the results of his labors.




1. Archives of Guadalajara, Document 1197. February 16, 1769. Cabo de San Lucas. A letter from Don Jose de Galvez to the Marques de Croix, telling of the arrival of Surgeon Pedro Prat and his departure on the San Carlos. Also a list of the medicines taken aboard.

2. The journey of the San Carlos is well described by two of the participants: The Diary of Miguel Costansó, edited by Frederick J. Teggart, Publications of the Academy of Pacific Coast History, 1911, volume 2, pp 161-325; and The Diary of Vicente Vila, edited by Robert S. Rose, Publications of the Academy of Pacific Coast History, 1911, volume 2, pp 1-119.

3. Archives of Guadalajara, Document 1440. January 7, 1770, San Blas. Jorge Estorace (No. 8). A Record of the Merchandise and Goods which are Embarked on the Ship San Jose, also called the Discoverer, with Destination to the West Coast of California Where It Is To Be Delivered to the Surgeon Pedro Prat.

4. A Treatise on Scurvy. By James Lind. London: Eusebius, 1753.

5. Orthomolecular Psychiatry. By David Hawkins and Linus Pauling. San Francisco: Freeman, 1973.

6. Representations: An Account of the Condition and Needs of the Missions by Father Junípero Serra, Mexico City, 1773. Article 28.

Author’s note: I am indebted to Helen Gohres of Chula Vista for copies of the documents from the Guadalajara Archives. These documents were obtained through the cooperation of the Bancroft Library in Berkeley.

Dr. Clifford Graves is a surgeon in La Jolla. He has written two other articles for the Journal of San Diego History. The first, in July 1964, was a sketch of Dr. David Hoffman. The second, in April 1968, was a jaunty piece on the Hon. J. Fortescue, ret.