of the green turtle are held in great esteem wherever they are found. The mother-turtles lay three times a year, depositing sometimes as many as a hundred eggs at a laying, and carefully covering them up with sand, so that it requires an experienced searcher to detect them. The Indians of the Orinoco and Amazon obtain from these eggs a kind of clear, sweet oil, which they use instead of butter. About five thousand eggs are required to fill one of their jars with oil; yet so abundantly are they deposited that about five thousand jars are put up yearly at the mouth of one of the rivers; the harvest is estimated by the acre. Young eggs are frequently found in the bodies of slain turtles by hundreds, in all stages of development, and generally consisting entirely of yolk; they are often preserved by drying, and are considered a great luxury. Alligators' eggs are esteemed by the natives of the regions where those reptiles abound; and Mr. Joseph, in his "History of Trinidad," says that he found the eggs of the cayman very good. The female alligator lays from one hundred and twenty to one hundred and sixty eggs; they are about as large as the egg of a turkey and have a rough, shell filled with a thick albumen. One of the lizards, known as the iguana, is capable of furnishing as many as fourscore eggs, which when boiled are like marrow. The larvæ and nymphæ of ants are considered by many people a choice relish when spread upon bread and butter, and are said to be excellent curried. In Siam they are highly esteemed, and are so valuable as to be within the reach only of the rich. In some parts of Africa, where ants swarm, they are said to form at times a considerable proportion of the food-supply. They are used in some countries of Europe for making formic acid, and are subject to an import duty. The eggs of insects belonging to a group of aquatic beetles are made in Mexico into a kind of bread or cake called, hautle, which is eaten by the people, and may be found in the markets. They are got by means of bundles of reeds or rushes, which are put in the water and on which they are deposited by the insects. Brantz Mayer, about forty years ago, noticed men on the Lake of Tezcuco collecting the eggs of flies which, he says, when cooked in cakes were not different from fish-spawn having the same appearance and flavor. "After the frogs of France and the birds' nests of China, I fancy they would be considered delicacies, and I found they were not disdained on the fashionable tables of the capital." According to the report of the Commissioner of Agriculture for 1870, the larvæ of a large fly which frequents Mono Lake, in California, are dried and pulverized and mixed with acorn-meal and baked for bread, or with water and boiled for soup.
Sanitary Inspection of Houses.—Mr. Lewis Angell, Sanitary Inspector of West Ham in Essex, an outlying district of London, says, in illustration of the prevalence of sanitary defects even in the best houses, and of the need of thorough inspection, that in the civic palace of the Lord Mayor or of London, "three quarters of an inch of floating fungi scurf was recently found on the surface, and three eighths of an inch of mud at the bottom of the cisterns, while a bottle of water on his lordship's table contained hundreds of nematoid worms." Offensive mud and animal organisms were also found in the cistern of the Athenæum Club, St. James. We habitually defy disease when we leave the doors of our closets open and the windows shut. The reverse ought to be the practice. He believes that sanitary science should be put on a par with literary and mathematical studies in the schools, and that public and official inspection should be provided for everywhere, the expense in the care of new buildings to be met by fees charged upon the owners and builders, who expect to derive a profit from them. He commends what has been done in Chicago in the official inspection of tenements, and the official supervision of plumbing that has recently been adopted in New York.
The Screw-Propeller.—The people of Boulogne, France, have recently set up a statue of Frédéric Sauvage, to whom they ascribe the invention of the screw-propeller. He devised a means of propulsion by screws in 1832, and offered it to the French Government. A commission reported upon it that it might be employed with advantage