As Captain Andrés said, the Spaniards in the port of Callao did not refuse the arrival of a ship full of Chinese goods, especially since among the goods brought on board were, in addition to silk and iron tools, 150 quintals of mercury.

As a necessity for the extraction of silver, mercury has been a sought-after commodity in the two colonies of New Spain and Peru. A load of mercury is worth 805 pesos in New Spain and 108 pesos in Peru. According to Zheng Zhihu's understanding, a load of mercury in Manila is about 40 yuan, and in Guangzhou it will not exceed 30 yuan per load, but in Yunnan-Guizhou and other mercury producing areas, it is between 18-20 yuan a load.

Mercury trafficking from China is nearly three times the profit. However, mercury had always been monopolized by royal merchants as a necessity in the mines, and silk and porcelain trafficked from China were more profitable, so mercury was only a dispensable supplement to the Manila galleon trade.

However, after entering the 17th century, the mercury mines in Spain began to dry up, and the mercury production in the local mercury mining area of Ouineavelica in Peru also continued to decline, which seriously affected the silver production in the Americas, which had begun to decline.

After nearly 100 years of mining, the silver mountains in northern Mexico have gone deeper and deeper into the ground, and after the easy areas have been mined, the remaining areas are hard-to-mine areas below the water table, so the cost of silver mining has risen and production has begun to shrink.

As a result, in the 20s, there was a silver crisis in the Spanish colonies in the Americas, which was fundamentally due in part to the fact that the colonies did not continue to discover new silver mines.

But the more reason is that the Spaniards exploited silver minerals in a predatory manner, which greatly wasted the silver reserves of many mines. The lack of mercury supply has exacerbated the crisis.

The princes and nobles of Spain understood that the entire Spanish Empire was a pyramid built on precious metals in the Americas. Once the precious metals from the Americas are lost, the vast empire will be in ruins in an instant.

Since the Spanish set foot on the Yucatan Peninsula, rich silver and gold deposits have been discovered by colonists. After hundreds of years of repetition, the Spaniards have long forgotten that even if the land of the American continent is too vast, there will be an end of exploration.

In the 17th century, the fact that new gold and silver mines could no longer be discovered first caused panic among the Spanish elite. A hundred years ago, the Spanish crown financed Christopher Columbus's voyages, both to find a trade route to the East and to find a land that would bring wealth to Spain.

Although Columbus did not arrive in China, he discovered the richness of Mexico. At that time, the Spaniards had not lost the courage and perseverance to open up a new land, and they moved a large number of people from the country to the Americas, indeed hoping to turn this land into the Spain of the New World.

But the constant appearance of silver and gold mines undoubtedly destroyed the Spanish crown's plans to develop New Spain. Every Spaniard's first day in the New World is either to find a new mine or to extract more wealth from the native people.

This impetuous mood made the Spaniards lose interest in running New Spain, and they ignored the other riches that existed in the land except silver and gold. As a result, with the exception of the Yucatan Peninsula, which was initially developed, the rest of the colony was entirely dependent on the existence of mines.

It is better to say that New Spain and Peru are colonies of the Spaniards than that they are huge mining companies. Without the gold and silver mines, these two rich colonies would not even be able to sustain themselves.

For the Kingdom of Spain, the regular annual shipment of gold and silver from the Americas was more than just the backbone of the Spanish economy. Most importantly, it is also a reassuring pill. Since the beginning of the last century, the Spaniards have been locked in one war after another, with the Moors of North Africa, the Ottomans of the Mediterranean, the British, the Dutch, the German and Northern European Protestants, and now about the French.

This continuous war not only destroyed the Spanish economy, but more importantly, left the entire kingdom in debt. And the reason why the Kingdom of Spain was able to barely support its domestic economy and continue to fight the Dutch and Protestants was because there were still people in Europe willing to lend them money.

These people lent money to the Kingdom of Spain, of course, not because the Spaniards were handsome, but on the basis of confidence in the gold and silver mines of the Spanish American colonies. If one day, something happens to the treasure ship coming from the Americas, it will be a major blow to the Spaniards.

And if there were rumors of the depletion of gold and silver mines in the American colonies, the merchants' purses would soon be closed to the Kingdom of Spain. Therefore, in order to ensure the amount of precious metals shipped back to the American colonies each year, the kingdom has become more and more strict in controlling the foreign trade of the American colonies.

At the same time, in response to the silver crisis, the Spaniards intensified their conquest of Colombia, on the one hand, in order to unite Peru with the colony of New Spain and facilitate domestic control of Peru.

On the other hand, they wanted to be able to discover large silver mines like Potosi in the newly conquered region. In order to prevent colonial officials from concealing the output of the mines, the kingdom tightened its control over the mercury trade.

In addition to a small part of the mercury from the local Huancavellika mine, the largest source of silver from Peru comes from Mexico. Thanks to the greed of the Gajupine people in Mexico, the price of mercury per quintal in the Lima market has risen from the usual 108 pesos to 188 pesos.

And this price is still priceless, and the mercury that Zheng Zhihu brought is actually not much, but it has attracted the attention of Lima officials. After an official from Lima came forward to buy all the mercury on his ship, he also had a private conversation with Zheng Zhihu. The official told Zheng Zhihu that as long as he carried no less than 200 quintals of mercury with him every time he came to Callao, he would be able to complete his normal transactions in Lima without being disturbed by the tax collectors of the kingdom.

Zheng Zhihu was deeply impressed by the opulence of Lima, and the wealthy merchants and officials here liked to ride in horse-drawn carriages decorated with silk and gold. This kind of carriage is worth 3,000 pesos in Lima, but according to Zheng Zhihu's calculations, it can be made for only 5 or 600 yuan in China.

However, the wealthy businessmen and officials here can travel in such a carriage on the street, but in China, Zheng Zhihu does not think that there is a wealthy businessman who dares to travel in such a carriage. It's not that I'm afraid of revealing my wealth, but it's the nouveau riche taste of these Spaniards, and even he can't stand it as a pirate.

Zheng Zhihu didn't stay in Lima for long, and after spending four or five days to complete the deal, he returned to the port of Callao and then set sail back. Although local Peruvian officials allowed Zheng Zhihu to trade there, they also restricted Zheng's movement in Lima.

Moreover, the prices in Lima are so high that even Zheng Zhihu feels a little unbearable. After buying a batch of locally produced wine, he left in a hurry.

Compared with the trip to the south, the voyage to the north was calm. The cold snap off the coast of Peru led Zheng Zhihu's ship northward even faster than before.

This allowed Zheng Zhihu to return to Alpulco in early May. At this time, the port of Alpulco had reached the end of the trading season, although the appearance of Zheng Zhihu aroused some interest in some "Gaqiuping" merchants.

However, the news that Zheng Zhihu's ship was carrying only some wine soon made these "Jiaqiuping" merchants leave in disappointment.

Captain Andrés was very enthusiastic about Zheng Zhihu's successful return. In this operation to act as an intermediary for Chinese businessmen, he received far more benefits than others.

Andrés only did a cursory calculation, and knew that the income he had obtained this time was enough for him to buy a piece of land to build a small estate.

This is entirely because these Chinese did not ask too much for hard currency such as gold and silver, but chose some Mexican flora and fauna. Compared to the value of the goods he provided, the goods given to him by the Chinese were almost free of charge.

In Mexico, a piece of Chinese silk costs 8 or 9 pesos, even if it is ordinary. And he got nearly 4,000 horses of all kinds of silk, which alone was worth more than 30,000 pesos.

Therefore, Andres is more thoughtful in his service to the Chinese. With his help, the Chinese who went to the Mexican highlands returned safely to the port of Alpulco.

And the tax collectors who appeared in the ports during the trade season did not bother these Chinese, in general. Captain Andrés proved to his Chinese friends that the goods they paid for were indeed worth the money.

In mid-May, Captain Andres and the soldiers of Fort San Diego reluctantly bid farewell to Zheng Zhihu and others. Captain Andres not only agreed to give convenience to the Chinese coming from the direction of the California Peninsula, but also agreed on a code with Zheng Zhihu.

If Zheng Zhihu didn't come in person next time, with this code, Captain Andres would also give someone to help.

The return journey from Alpulco to Manila was not difficult because of the hired Spanish sailors who guided the way, and the ocean currents played by the ocean currents.

After passing through the Marshall Islands Reef and the Caroline Islands, the Philippine Islands are in sight.

However, on the return trip, because all the canned food had been consumed, the crew still had symptoms of sepsis.

However, the voyage had already been developed by the Spaniards, so the ships were able to get some fresh food along the way, and in the end there were no dead people.

To the east of the Philippine Islands, the fleet encountered pirates for the first time, but when these pirates in small boats recognized Zheng Zhihu's flag, they finally chose to retreat.