Since coming to the Ming Dynasty, Shi Yiwen's days have passed freely.

But while he was at ease, he realized the hard work of the ancients. As the weather gets hotter, mosquitoes become more and more rampant.

For Shi Yiwen, the night is his most tormented time.

With the increase in cotton oil production, soap production is on the right track, as for the previous competitors, because of the negotiation with Tang Ziqi, and ended the previous competition, soap is selling more and more, and cotton oil production has also reached a new level, ensuring the supply of soap raw materials, soap factories or not, oil mills usually do not need Shi Yiwen to bother much, seeing that he can't sleep well all night, he finally pulled out to solve the current problem that plagues him.

Looking at the wild grasses and wild trees all over the mountains, especially when he saw the vine-like shrubs scattered all over them, Shi Yiwen's eyes flashed with a fine light. These inconspicuous shrubs will not only help him solve his problems, but they will also bring extremely rewarding ones!

"Young Master, what are we doing here??"

Seeing the young master's eyes staring at the weeds and trees on the mountain, Xiao Pian asked puzzled.

"Young Master, don't you want to buy land? Although the mountains are cheap, they are of little use. ”

"Buying land?"

Hearing this, Shi Yiwen was stunned for a moment, and then smiled.

"It's not impossible to buy land, but you always have to pay money to buy land, and now we don't have to spend a lot of money to buy land!"

Casually broke off a small piece of wild vine, Shi Yiwen pointed to the wild vine in his hand and said.

"Xiao Pian, you see, what I need is this thing, young master, with it, young master, I can earn a lot of silver!"

"Use it? Can you earn money? ”

Xiao Pian looked at the wild vine in the young master's hand in puzzlement, and asked tentatively.

"Could it be medicine?"

"Yes, but it's not an ordinary medicine, it's an insect killer!"

Holding the wild vine in his hand, Shi Yiwen said quite proudly.

"The mosquito smoke in the market now is nothing more than relying on the moxa wool inside to smoke mosquitoes, and arsenic to kill mosquitoes, because a lot of moxa wool is used, so it is smoky to burn, as for the arsenic in the mosquito smoke, it seems to be a trace amount, but it will accumulate over time, and it will also cause harm to the human body."

After lighting the mosquito coil of this era for the first time, looking at the choking smoke, when he learned that there was arsenic in the mosquito coil that seemed to be made of mugwort wool - that is, mugwort leaves, Shi Yiwen, who cherished his life, let people hang up the mosquito net for the first time.

Because of the season, mosquito coils were not found in the supermarket. So, I had to figure it out on my own, and after a few days of flipping through books in the library, I found a relatively suitable plant in a preventive medicine journal - bitter bark vine. This plant is widely distributed in China. Bitter bark, vine root bark and stem bark can be used to extract insecticides and sterilizers.

"If you use it, you won't do any harm to people, it's ......"

Looking at the wild trees all over the mountains and the bitter bark vines mixed in them, Shi Yiwen muttered to himself.

"If you want to collect its stem bark, I'm afraid it will take some work."

In fact, it is not troublesome to collect the stems and barks of the bitter bark vine, because many papermaking workshops outside Nanjing use the bark of mulberry bark and bitter bark vine to make paper, so at the foot of the mountain there are people who rely on harvesting the stems and barks of the bitter bark vines, as long as they spend a few hundred dollars, they can buy the stems and skins of the bitter bark vines.

Even the stems and skins of those hundreds of catties of bitter bark vines are also the stems and skins that have been dried to pick out impurities, and these stems and skins have been handed over to a nearby papermaking workshop by Shi Yiwen, and they have been entrusted with thousands of hammers in a water-powered stone mortar to make the stems and skins into fine velvet.

In the next few days, the charcoal powder and clay-based ash powder from the charcoal field at the foot of Zhongshan Mountain were sent to the home, and even mosquito coil molds were made.

After pressing the mosquito coil into an indentation with a copper mold and "baking" it in the kitchen oven for an hour, after the mosquito coil similar to the mosquito coil of later generations was taken out, Xiao Lian and Kou Yun all looked at the mosquito coil on the stone table attentively.

"Young master, how can such a plate of mosquito coils be burned like a round cake?"

"This is simple, this mosquito coil looks like a round cake, but it is actually a disc shape composed of two mosquito coils tightly surrounding each other, as long as you gently fall, shake, and then ......"

After dividing this mosquito coil that borrowed from the structure of mosquito coils in later generations into two plates, looking at this mosquito coil that condenses his own efforts, Shi Yiwen was quite proud.

In fact, there is nothing mysterious in this plate of mosquito coils, it is nothing more than the stem and skin of the bitter bark vine are smashed into powder, mixed with a small amount of clay, charcoal and leather glue, and then pressed into a plate with a mold, and then baked and carred in the oven, a plate of "invincible" mosquito coils was born.

"Well, you see, this is divided into two plates, and then put it on the stand, light one end, such a plate of mosquito coils, I estimate that it should be no problem to burn for four or five hours, this mosquito coil does not contain arsenic, so it will not hurt people, and more importantly, it is not like the current mosquito coils, which can smoke people into African chickens."

Shi Yiwen, who was quite proud, didn't care if a few little girls knew what an "African chicken" was, he just proudly displayed mosquito coils, and the only thing he regretted was probably because there was no mosquito coil stand made of iron sheets.

As soon as his voice fell, he heard someone behind him say.

"Mosquito smoke in the wild shop, the official road is loose and blows long", every summer, burn the mosquito smoke, one is not careful, it is possible to walk the water, sometimes, the smoke in the house is big, people have not run out, the smoke is burned into a fire, and the people and the house are all in flames......"

Raising his head, Shi Yiwen saw an "old acquaintance" he hadn't seen for a while, Liu Nengde, Liu Zhen's envoy, holding a gift box in his hand. But I hadn't seen him for a while.

"Brother Liu, who are you?"

Hurriedly stood up, Shi Yiwen said in surprise.

"Shi Gongzi, thank you Gongzi for his wonderful rejuvenation, Neiko's condition has now healed. When I came back from Kyoshi this time, Uchiko specially instructed me to thank Childe! ”

Although there was gratitude in his tone, Liu Nengde, who knew that the great grace was not grateful, did not continue, but directly picked up a plate of mosquito coils, looked at it for a while, and then said.

"This mosquito coil made by Gongzi, if it is smokeless and can kill mosquitoes, there is a doorway to send the mosquito coil to the palace, no matter how bad it is, this Nanjing lord's mansion can also be sent in, as long as the powerful and wealthy use it, when the time comes, as long as the price is right, ordinary people will definitely compete to use it first, and at that time, the mosquito coil of the miracle doctor will definitely be popular in the world."

Wanli was a society with an extremely strong commercial atmosphere, even Liu Nengde, who was the envoy of Jinyiwei Nanjing Town, was talking about business as soon as he opened his mouth, of course, he said so much, obviously to repay favors. Although these are not worth mentioning compared to that favor.

"Oh? Brother Liu, are you interested in trying it together? ”

Looking at Liu Nengde curiously, Shi Yiwen didn't expect this vulgar-looking man, when it comes to doing business, he can't even think of such an idea.

"Let's try it together? What do you mean? ”

Liu Nengde said strangely. Looking at Liu Nengde, who was surprised, Shi Yiwen smiled.

"That's it, if you want to do the mosquito coil business, when the time comes, Brother Liu will be the partner of the younger brother, what do you think?"