"We now know that burning of every sort always produces this same carbonic acid gas.""I think," added Fred, "you have seen me breathe into a tumbler of lime-water, and turn the water white and milky-looking? That proves that carbonic acid is given off with my breath. Teacher says that not only we, but all animals breathe out carbonic acid gas."SUMMARY
Carbonic acid is an invisible gas, without either taste or smell. It is very heavy, and can be poured out like water. It extinguishes a ?ame. Nothing can burn in it. It turns clear lime-water white, like milk. Carbonic acid is formed when burning of any sort goes on. Animals send out carbonic acid when they breathe.
Lesson 43
More about Insects
"Shall we see what else we can find to say about insects, Fred?" asked Willie. "Norah would be pleased, I am sure.""Very well," said Fred, "suppose we talk about the insect"s body. The most important part of the body is the chest. To it are joined the wings above and the legs on the under side.