"Husband, do you know why we can save silver?" An Jing suddenly changed the subject, asking Xiao Changyi.
Xiao Changyi shook his head. Saltpeter isn't cheap either. To freeze water into ice, he estimated that a considerable amount of saltpeter would also be needed each time.
An Jing giggled to herself for a while before saying, "Because saltpeter can be reused, we don't need to spend money to buy a lot of saltpeter."
"Reused?" A spark of interest lit up in Xiao Changyi's cool eyes.
"Mhm!" An Jing nodded emphatically. "Even though saltpeter dissolves in the water and turns the water into ice, the ice or water that contains saltpeter can be dried in the sun to recover the saltpeter. Then, the saltpeter can be put back into the water to make ice... Isn't that reusing it?" As she spoke, An Jing tilted her chin up proudly.
Xiao Changyi's lips curled slightly, "How do you want me to praise you?"
An Jing immediately smiled, "No need for praise, just a kiss will do."
