What's the hard shell in the barrel?

1770 In the summer, the weather in Sweden was extremely hot. One day, several barrels of wine arrived from Xia Lang Berg Pharmacy in Stockholm. The workers are unloading heavy barrels from the carriage. At this moment, a young pharmacist in the pharmacy came over. He opened the lid of the bucket and looked at it carefully. The quality of the wine was excellent, but after exposure all the way, a thick reddish shell was formed on the barrel wall.

"Hey, what is this?"

Obviously, this hard shell has aroused the interest of pharmacists. He scraped off some hard shells and took them back to his room.

The pharmacist's name is Scheler. /kloc-started working as an apprentice in a pharmacy at the age of 0/5. Scheler has never been to college, but he is eager to learn, especially interested in chemistry, and likes to do various experiments. He made use of the rich library and convenient working conditions of the Shalanberg Pharmacy, taught himself many chemists' works, and personally tested the chemical properties of many substances.

In the evening, Scheler excitedly called his friend Lezius. Rezius is a young college student. He and Scheler have the same interests and hobbies. They often discuss problems together and do various experiments. Scheler took out the hard shell scraped from the barrel. They dissolved the hard shell in sulfuric acid by heating and precipitated crystals after cooling.

Hey! What is this red shell? Looking at this crystal, Scheler and Lezius can't help wondering: What is this? Does it taste sweet or bitter? Scheler thinks that since it is extracted from the sediment of wine, it is probably not toxic. He decided to taste it himself, so he picked up a crystal and licked it gently with his tongue. Well, it turns out to be neither sweet nor bitter, and it has a taste similar to sour grapes. They dissolved the crystal in water again. After several experiments, they found that it had a lot of acidity. So Scheler and Lezius named it "tartaric acid".

After tartaric acid was successfully extracted, the two young people wrote their findings in a paper with great interest and sent them to the Academy of Science of the Royal Swedish Academy. Who knows, the secular concept made the research results of these two unknown young people met with a cold shoulder, and their papers were put aside and nobody cared.

Scheler waited for a long time and did not receive a reply from the Royal Academy of Sciences. However, he did not lose heart. Scheler thinks that there must be many unknown acids in plants in nature. So he extracted many kinds of acids from plants according to the method of discovering tartaric acid. 1776, he made oxalic acid; 1780 to prepare lactic acid and uric acid; 1784 to prepare citric acid; 1785 to prepare malic acid; Gallic acid was prepared in 1786. As for tartaric acid, which they first discovered, it was not buried for a long time. Later, it was mainly used in food industry, such as making drinks. Tartaric acid can also be combined with various metal ions and used as a cleaning agent and polishing agent for metal surfaces.

You see, one success after another comes from the hard shell accidentally deposited in the barrel, doesn't it?