Black gunpowder with sugar added

Li Shimin and his companions talked late into the night. Throughout their conversation, Li Zhi offered many unique insights. For example, he suggested reclaiming temple land ownership and requiring those who joined monasteries to relinquish their land holdings. This would effectively prevent able-bodied young men from escaping labor duties by seeking refuge in temples as monks. He also proposed defining temple operations as commercial enterprises and taxing them accordingly. However, the interests involved were so numerous that Li Shimin needed to study the matter carefully.

Yet another idea from Li Zhi won the wholehearted approval of both Li Shimin and Sun Simiao: the establishment of a dedicated academy of medicine, inviting renowned physicians from across the empire to teach, and organizing the compilation of a medical compendium to preserve the medical wisdom of the Tang Dynasty. Li Zhi further recommended granting these physicians official status to elevate their social standing. Initially, Li Shimin doubted this proposal. He remarked, “Granting so many official titles might provoke discontent among the ministers.”

To his surprise, Li Zhi replied bluntly, “Whoever dares to oppose, let every doctor in the land refuse them treatment—then we’ll see who’s stubborn.” Li Zhi’s bold demeanor made both Li Shimin and Sun Simiao laugh. Still, his solution was indeed a good one.

Once Li Shimin agreed to found the medical academy, he earnestly invited Sun Simiao to serve as its first director. After much polite refusal, Sun Simiao finally accepted. With the Empress Changsun about to give birth, Sun Simiao temporarily took up residence in the Imperial Medical Bureau, giving Li Zhi more opportunities to interact with him.

During this period, Li Zhi not only learned many remedies and alchemical techniques, but also subtly introduced concepts such as extracting medicinal essences and surgical theories during his questions, planting these ideas in Sun Simiao’s mind.

Sun Simiao stayed at the Imperial Medical Bureau for more than half a month, leaving only after the Empress gave birth safely. He then set about organizing the medical academy, welcoming distinguished doctors from all over and recruiting students. Li Zhi, meanwhile, began his solo research into black powder.

With Sun Simiao’s endorsement, he could openly instruct Liu An to gather materials for making black powder. Though these substances differed somewhat from what Sun Simiao had described, Li Zhi could easily cover up the discrepancies.

Besides the essential saltpeter, sulfur, and charcoal, Li Zhi also asked Liu An to procure some expensive cane sugar.

According to Liu An, the sugar was imported from merchants in India and sold at a high price in the Tang Dynasty. Li Zhi scoffed inwardly upon hearing this: it was merely minimally processed brown sugar—how could it fetch such a price? People of this era truly had little exposure to finer things. Of course, he did not let Liu An see this reaction.

He had already decided that once his research on black powder was complete, he would also summarize the methods for producing refined salt and white sugar. Not only would this allow the people of Tang to enjoy better salt and sugar, but he could also export these products to other countries and reap substantial profits.

To avoid arousing suspicion, Li Zhi delayed several more days before preparing all the necessary black powder ingredients.

On that day, he brought out the blended black powder and said to Liu An, “Go find a few empty wine jars. We’re going to make something interesting.”

Liu An, puzzled by the secrecy, asked, “Your Highness, what needs wine jars?”

Li Zhi replied, “Just wait and see—once it’s done, it’ll surprise you.”

Seeing Li Zhi’s reluctance to explain, Liu An stopped asking and dutifully went to find empty jars.

Meanwhile, Li Zhi used rice paper to make several long fuses, intended for detonating the black powder. Liu An quickly returned, carrying four jars, each able to hold about two pounds of wine.

Finding the size just right, Li Zhi and Liu An set to work. They filled the jars with powder, bored a small hole in each lid, and threaded a fuse through the opening.

Once everything was ready, Li Zhi said, “Go hitch a carriage; we need to head out of the city.”

Liu An grew nervous at the prospect of leaving town. He frowned and advised, “Your Highness, the countryside is unsafe. Let me go alone instead.”

Li Zhi replied, “We won’t go far—just find a secluded spot outside the city.”

Still hesitant, Liu An was about to object when Li Zhi added, “I haven’t yet figured out the temperament of this substance; I must witness it firsthand to gauge its effects.”

Hearing this, Liu An took a deep breath and said, “If Your Highness insists, I’ll accompany you.”

He resolved privately that if they encountered danger outside the city, he would risk his life to hold off any attackers so Li Zhi could escape.

Thus, Liu An anxiously escorted Li Zhi beyond the city gates. Li Zhi chose a patch of wild grass and told Liu An to stop.

Once the carriage halted, Liu An saw they were not far from the city walls, and his heart finally eased.

Li Zhi still hadn’t explained what they were making. He instructed Liu An to place one jar amidst the tall grass.

Because the thick weeds impeded his movement, Li Zhi handed the task of lighting the fuse to Liu An.

At that moment, Liu An was unaware of the danger of explosives. He followed Li Zhi’s instructions, ignited the fuse, and then quickly ran back to Li Zhi’s side.

Just then, Li Zhi suddenly said, “Cover your ears, quickly.”

After speaking, Li Zhi covered his own ears first.

Liu An was a beat slow; he had just covered his ears when a deafening boom erupted.

The sound nearly made him drop to his knees in fright.

He watched in shock as earth was hurled up from the spot where the jar had been placed, accompanied by fire and thick smoke.

Liu An stiffly turned his head toward Li Zhi, who seemed utterly unafraid.

He asked in amazement, “Your Highness knew this would explode?”

Li Zhi, walking toward the blast site, answered, “I suspected as much.”

Li Zhi would never admit he knew for certain that it would explode; otherwise, he would seem too mysterious.

At this point, even Sun Simiao, an expert in the field, only surmised that such substances could explode but had not formulated the recipe for gunpowder.

Strictly speaking, Li Zhi had appropriated Sun Simiao’s achievement and improved upon it.

Seeing Li Zhi approach the blast site, Liu An hurried ahead to shield him, reminding, “Be careful, Your Highness.”

Li Zhi smiled and said, “Don’t worry—it won’t explode again.”