The city lord listened to Zhang Hao's suggestion, was silent for a while, and a faint smile appeared on his sad face, like a ray of sunshine in the dark clouds, full of hope.

He patted Zhang Hao's shoulder hard, "I suddenly understand why General Wu is optimistic about you." This suggestion of yours, I will immediately pass it on to General Wu. ”

Of course, Zhang Hao had to be modest: "It's just a little immature suggestion, if you want to really implement it, you still need an experienced person like the city lord." ”

"Haha......" The city lord laughed, but after a while, his face became serious again: "Zhang Hao, there is news for you." ”

"What?" Zhang Hao's heart lifted.

"You're famous. Now everyone knows that after hearing about the princess, you vomited blood, and some people even said that you vomited blood and fell unconscious. ”

Zhang Hao: ......

Until he left the City Lord's Mansion, Zhang Hao's face was dark, who was so gossipy, how could such information spread all over the streets? No wonder when I just entered the city, the people along the way looked at me so strangely.

This is not ashamed in the future, and the streets are full of ~~~

Zhang Hao returned to the guild with Zhu Yuantang, and Zhu Yuantang would come to negotiate on behalf of the City Lord's Mansion, and the results of the preliminary negotiations would be submitted to the Imperial Court.

The Zhang family already had a mature credit clause, and Zhu Yuantang himself had participated in the discussion, and the new credit clause was quickly drafted. The main thing is the addition of the clause of the tax mortgage.

Until the emperor's reply is received, it can only be drafted. Then Zhang Hao hurriedly returned to the family, and there were still too many things to be busy at home.

The situation is so critical, Zhang Hao must strengthen the Zhang family as soon as possible. To put it mildly, as long as the Zhang family is strong enough, even if the country of Qixia is destroyed, the Zhang family can negotiate conditions with the country of Taihua or the country of Canglan and continue to survive.

Since the era of the country, the land of Qixia has also undergone several changes. But there are so many families and sects that have been prosperous for a long time.

For example, the Ouyang family, where the prime minister is located, no matter how the dynasty changes, their support is indispensable for the new country.

This is the power of the family, a power that is very different from the state.

Even if the emperor hated the existence of the Ouyang family and the Jiuyang Sect, he still had to greet him with a smile.

In this world of cultivation, it is said that there is a 'family and a country in the world', and there is a family first, and then there is a country, and this order is not wrong.

Zhou Jue hadn't left yet, and when Zhang Hao came back, Zhang Shengde was discussing cultivation with Zhou Jue. Compared with the knowledgeable Zhou Jue, Zhang Shengde only has to ask for advice.

Zhou Jue himself is the young master of Xinglin Hall and the eldest disciple of Jiuyang Sect, and the words 'family origin' are no longer enough to describe. But Zhang Shengde was born in the wilderness.

Zhou Jue talks and laughs freely, but he doesn't hide his selfishness, except for the core of the sect and family, the rest is endless.

Zhang Hao came over to pay a visit, and hurried back to the smelting base.

Regarding Zhou Jue's thoughts, Zhang Hao faintly understood: saying something about cultivation did not lose anything to Zhou Jue, but it could win over the Zhang family.

Just Zhang Hao's identity as a registered disciple of the Xuanzhen Sect is not trivial. What's more, the Zhang family's Xuantie smelting ability is enough for Zhou Jue to put on a smiling face.

And if the Zhang family wants to really climb the high branch of Zhou Jue, the best way is to produce high-purity dark iron.

Exchanges between families, interests come first.

When Zhang Hao came to the rudimentary research room, he was surprised to find that Huang Mingshan and others were already experimenting with quicklime water.

Seeing Zhang Hao, Huang Mingshan shouted excitedly: "Young master, we found that after the burning air, after being injected with quicklime water, the volume has shrunk by about a quarter. ”

In other words, the oxygen content of the air in this world is about 25%?

Zhang Hao watched the experiment of Huang Mingshan and others, and the beakers were polished with translucent quartz stone. Glass...... Not for the time being, and Zhang Hao doesn't want to produce glass now.

When the Zhang family is truly stable, they can completely protect their wealth, and it is not too late to produce glass. Now it is enough to have quartz and so on for experiments. Anyway, there are specially polished magic weapons, there are spells, and it is not troublesome to polish these tools.

Under Zhang Hao's supervision, Huang Mingshan conducted another experiment.

The upper layer of the flask is directly closed with a small spell, then a piece of red-hot charcoal is inserted, and after waiting for a long time to make sure that the charcoal has not changed, the flask is led into lime water.

I saw the lime water rise little by little, and finally occupy about a quarter of the volume.

And the lime water has become cloudy.

It's a very simple experiment, but it's this simple experiment that can open the door to chemistry.

Zhang Hao didn't speak, but picked up a quartz tube in the middle and blew it into the lime water, and saw that the lime water also began to be turbid.

"This ......" Huang Mingshan and the others were surprised.

Zhang Hao smiled: "I've been wondering, is there a reaction similar to combustion in our bodies? Okay, this problem will be discussed later, what we need to do now is to get high-purity dark iron."

Let's do an in-depth experiment, what happens if we insert a red-hot iron bar into a flask?"

At the beginning of the test, it was seen that there was obvious rust on the surface of the iron bar, and the seal on the mouth of the bottle began to dent.

Until the iron rod no longer changes, place the flask upside down in lime water.

This time, the lime water instantly rose to a quarter position, and the lime water did not become muddy.

Huang Mingshan pondered: "There is a certain ingredient in the air that can be burned with charcoal, or it can make iron rust. and charcoal combustion produces an equivalent amount of gas, which can make lime water turbid. After reacting with iron, solid rust is formed, and this part of the gas disappears directly.

And it seems that we need this part of the gas to breathe. ”

Zhang Hao nodded with a smile.

Huang Mingshan was encouraged, thoughtful: "Could it be that this is the aura between heaven and earth?"

"Poof......" Zhang Hao squirted out a sip of tea, this turn is too big.

Huang Mingshan was a little embarrassed: "Young Master, isn't it aura?"

Zhang Hao covered his head, "If this is aura, then why do we have to add spirit stone powder when we smelt dark iron!"

"Oh, oh, oh......" Huang Mingshan also realized his mistake.

Chen Feng next to him suddenly said, "Is it the legendary life force?"

"Life Force Can Make Iron Rust?!" Zhang Hao rolled his eyes, but he patiently made everyone think.

This is the process of breaking out of the cocoon, and this process cannot be fueled by seedlings.

Liu Ming next to him jumped up: "I know, this is combustion!"

Zhang Hao continued to shake his head: "If this is combustion, then what is the gas produced by our calcined charcoal cube before and burning with a light blue flame?"

Huang Mingshan scratched his head and suddenly asked Zhang Hao, "Young Master knows?"

Zhang Hao smiled, but his words were categorical: "I don't know!"

But I know that your assumptions are wrong, because there are other explanations.

There is only one truth, and so is the answer.

You guys, you have to find that one and only answer!"

(The text says that the red-hot iron bar is rusty, not burning.) But thanks to the attentive readers. ）