Answer:
The earlier ways of getting fire were indeed dangerous. In the last two paragraphs, the author shows the readers two ways that we got fire. For the first way (by nature) they got it from lightning, or from a volcano. Because breathing in smoke is dangerous, too long in the smoke can damage your lungs. Since fires spread quickly, someone could catch on fire, and that would be the end. For the second part, once again, a fire could start anywhere, and spread quickly.
“Although Walker's match did not require the bottle of acid, nevertheless it was not a good one. It could be lighted only by hard rubbing, and it sputtered and threw fire in all directions”
In that sentence, it shows that it took some elbow grease to start a fire, and the sparks would fly everywhere, so it would be really dangerous.
Step-by-step explanation:
(you're welcome ;)