POPULAR MISCELLANY. 



141 



strata of littoral and estuary origin, to which 

 the name Potomac formation has been ap- 

 plied. These deposits are only a few hun- 

 dred feet thick, and, though frequently cov- 

 ered from sight, seem to be continuous from 

 New Jersey to Mississippi. Invertebrate fos- 

 sils are rare, but large collections of fos- 

 sil plants have been found in the Potomac 

 region. The best authorities recognize sev- 

 eral of these fossils as Jurassic. Briefly, 

 then, the Mesozoic of the Atlantic coast 

 region consists of a probable representation 

 of the Upper Trias of Europe, a possible one 

 of the Upper Jura, a probable slight one of 

 the Middle Cretaceous, and a practically 

 certain representation of a large part of the 

 Upper Cretaceous, with a hiatus between the 

 latter and the Eocene. The speaker advo- 

 cated a system of classification more suited 

 to this country than the European one. The 

 time has come when North American geolo- 

 gists can and ought to hold a commanding 

 position in this matter. 



Olives and their Oil. — The olive has 

 been cultivated in the regions of the Medi- 

 terranean coasts from time immemorial. Ol- 

 ive-oil there takes the place of butter. Spain 

 has about 3,000,000 acres in olives, Italy 

 2,250,000, and France about 330,000 acres. 

 Forty-five varieties of the fruit are described. 

 The tree occasionally grows to be sixty feet 

 high, and twelve feet in circumference of 

 trunk. The varieties differ in the nature of 

 the wood, the foliage, and the quality and 

 shape of the fruit. The fruit is mild, or 

 sharp, or bitter ; and the oils differ like- 

 wise ; so that a pure olive-oil may be unfit 

 for purposes of food, and only fit for greas- 

 ing machinery and making soap. The green, 

 unripe olives, having had the bitter taste 

 extracted with salt, are preserved in vinegar 

 with spices. The ripe olives are gathered in 

 the fall, when they are as large as common 

 plums. They are of dark-green color, and the 

 pit, now become a hard stone, contains a 

 savory kernel. The flesh is spongy, and its 

 little cells are filled with the mild oil, which 

 runs out at the least pressure. The finest 

 oil is the virgin oil which is made by col- 

 lecting the freshly gathered olives in little 

 heaps, and letting them press the oil out by 

 their own weight. It is clear, and has a deli- 

 cate, nutty taste, with little or no odor. When 



the fruits cease to give the oil by them- 

 selves, they are pressed with small millstones, 

 yielding an oil which is also clear and has a 

 pleasant taste. The olives, still rich in oil, 

 are next put in sacks, boiling water is poured 

 over them, and they are pressed once more. 

 The oil gained by this process is yellowish- 

 green, and has a sharp taste and an unpleas- 

 ant smell. At Marseilles the olive-oils are 

 classed into manufacturing oils for burning, 

 greasing machinery, and soap-making; re- 

 fined oil ; oil from the pulp or husks, and 

 table or edible oil. The last is superfine, 

 fine, half fine, and ordinary. The table oil 

 is refined by allowing it to run through lay- 

 ers of thin sheets of wadding into tin perfo- 

 rated boxes. The wadding absorbs all the 

 thick particles, and leaves the oil clear and 

 tasteless. The olive crop is variable and un- 

 certain, and is seldom profitable more than 

 once in six or eight years. 



Avogadro. — According to a sketch pub- 

 lished by Prof. Hugo Schiff, of Florence, in 

 the " Chemiker Zeitung," Amadeo Count 

 Avogadro, son of the magistrate Filippo 

 Vercellone, was born in Turin, August 9, 

 1776. He studied jurisprudence at the Tu- 

 rin University, became Doctor of Laws on 

 March 16, 1796, and then held a position 

 under the Government till 1S06, when he 

 began his scientific career. In physics he 

 was self-taught, and obtained a subordinate 

 position in the Collegio delle Provincie in 

 Turin, which was then and still is a richly 

 endowed department of the Turin Universi- 

 ty. On November 7, 1809, he became Pro- 

 fessor of Physics at the Gymnasium in Ver- 

 celli. In 1820 he was elected Professor of 

 Mathematical Physics at the Turin Univer- 

 sity. Later this chair of instruction was 

 abolished, and Avogadro resumed the prac- 

 tice of law. He was, however, reinstated in 

 his chair through the influence of Charles 

 Albert, and remained at the university till 

 1850, when he retired on account of old age 

 and ill health. He died at Turin, July 9, 

 1856, at the age of eighty years. Avogadro 

 was but little known in Italy and unknown 

 in foreign countries. He shared with Charles 

 Gerhard, who died in the same year, August 

 19, 1856, the same fate. It was only after 

 death that their great and important contri- 

 butions to science found recognition. 



