This doctor found out that what made the Isthmus so unhealthful was—what do you suppose?—nothing but little mosquitos. These mosquitos were different, however, from those we have that merely leave an itchy spot where they bite. The mosquitos down there were of an entirely different kind. Some of them were town mosquitos and some were country mosquitos. The country mosquitos gave people malaria, which was bad enough, but the worst kind of mosquitos were the town mosquitos. They gave people a terrible disease called yellow fever—a disease that turned people yellow and killed almost every one who caught it. So the doctor said I’ll find out how to get rid of the mosquitos and keep them from killing the people. Accordingly, he went after the mosquitos first, and this is the way he killed them. The town mosquitos he killed with sulphur smoke—sulphur from Popocatepetl—and the country mosquitos he killed with oil—oil from Mexico too. Then he cleaned up the marshes and other places where the mosquitos lived and raised their enormous families, so that they had no place to live, and in these ways he changed the Canal Zone from the most unhealthful place to one of the most healthful places

Then, and not until then, the United States went ahead and made the Canal. They didn’t cut the land straight through, however, as the French had started to do, so that the Atlantic and Pacific could run together—that would have meant too much digging, even with dynamite, for dynamite blows up land, and the land has to be carried away after it is blown up. So the United States dug a ditch across the Isthmus on top of the land and used a river and a lake already there to keep this ditch filled with water. At each end of this ditch or canal they made locks to raise ships from the sea at one end, and to lower them to the sea at the other. So ships now go across from one ocean to the other, but most of the way they sail on fresh water, for neither ocean runs into the other. Namerica and Samerica are not cut apart—they are still joined and always will be, until the Creator does the separating.