J0NE 2, 1911] 



SCIENCE 



871 



Maps were shown that gavr e depths of the 

 several oceans, the directions of their currents, 

 their temperatures at all depths, their salinity, 

 density and other physical conditions. The im- 

 portance of each of these phenomena was clearly 

 stated and their interdependence carefully ex- 

 plained. It was explained, for instance, that life 

 at considerable depths in the sea is dependent 

 upon vertical circulation, because in this way 

 only is it possible to bring to the lower portions 

 the necessary amount of oxygen. This explains 

 the absence of life in the deeper portions of the 

 Black Sea in which the distribution of density is 

 such that it produces horizontal currents only. 



Even those portions of the ocean farthest re- 

 moved from land have an abundance of animal 

 life, which in the last analysis must live upon 

 vegetable matter. But this, the lecturer ex- 

 plained, is everywhere present in such abundance, 

 though consisting of microscopic individuals, that 

 the oceans, may be thought of as vast meadows 

 containing even more vegetable matter than is 

 upon the land. 



A most interesting and possibly important fact 

 is the change, after a lapse of a few years, in the 

 temperature o± the deeper layers of the sargasso 

 sea. These temperatures should be taken several 

 times a year for a number of years, for the pur- 

 pose of determining whether the change is cyclic, 

 and what its causes and its consequences are. 



These are only some of the topics discussed in a 

 lecture that combined in the highest degree the 

 interesting and the instructive. 



The 70th meeting of the Washington Academy 

 of Sciences was held in the assembly room of the 

 Cosmos Club at 8:15 p.m., March 30, 1911. Presi- 

 dent F. W. Clarke presided. 



Professor Dr. Victor Goldschmidt, professor of 

 mineralogy in the University of Heidelberg, Ger- 

 many, presented a paper on ' ' The Nature of 

 Crystals. ' ' 



The lecturer began with humorous descriptions 

 of school-day experiences when we studied crys- 

 tallography by the aid of painted wooden and 

 pasteboard models, and from them got the idea 

 that real crystals were mighty poor imitations of 

 our beautiful wooden blocks. 



By way of emphasizing the importance of the 

 subject of crystallography it was stated that all 

 ice and snow, all rocks whether of mountains or 

 in the deep strata of plains, the moon, wandering 

 meteors and all solids from liquids, are crystals. 



A philosophical and all-comprehensive definition 



of crystals was then developed, and contrasted 

 with the similar definition of a liquid. A crystal 

 was defined as being : "A solid system of like 

 particles with like orientation. ' ' A liquid was 

 defined as "A system of gliding and rotating par- 

 ticles. ' ' 



Any one who thinks crystallography either an 

 unworthy or uninteresting subject is very much 

 mistaken. Dr. Goldschmidt declared, and by his 

 lecture, in the opinion of all who heard him, 

 made good this claim. 



W. J. Humphreys, 



/Secretary 



THE B0TANICAL SOCIETY OF WASHINGTON 



The 73d regular meeting of the society was 

 held at the Cosmos Club, Tuesday, May 2, 1911, at 

 eight o'clock p.m. President W. J. Spillman pre- 

 sided. Thirty-one members were present. 



Mr. Walter T. Swingle presented a review of a 

 recent paper by de Vries entitled "Ueber dop- 

 peltreziproke Bastarde von CEnothera biennis L. 

 und 0. muricata L., ' ' in Biologisches Central- 

 blatt, 31: 97-104, No. 4, February 15, 1911. This 

 review will appear in full in Science. 



The following papers were read: 



The Seoent Excursion into the Dismal Swamp: 



F. V. COVILLE. 



After describing an excursion made by the 

 Washington Academy of Sciences into the Dismal 

 Swamp of Virginia, April 28-30, 1911, the author 

 discussed the characteristic plant associations of 

 the Dismal Swamp which are those of the ' ' black 

 gum" and the "juniper" areas, the latter being 

 of unusual ecological interest. 



The ' ' jimiper ' ' lands of the Dismal Swamp 

 have a special flora different from the other floras 

 of the region. The characteristic tree is the 

 southern white cedar (Chamcecyparis thyoides), 

 locally known as "juniper." The common shrubs 

 are swamp blueberry {Vaccinium corymbosum), 

 white alder (Clethra alnifolia), inkberry (Ilex 

 glabra), fetterbush {Pieris nitida), and various 

 other species belonging to the heather famUy. 

 The soil is a red-brown peat, made up of the dead 

 roots, twigs and leaves of the swamp vegetation. 

 The water of these juniper swamps contains a 

 remarkably small quantity of mineral matter, and 

 has the color of tea, due to a dilute solution of 

 organic matter derived from the peat. When 

 tested with phenolphthalein the water gives an acid 

 reaction, to the degree of .0005 of a normal acid 

 solution. The peculiar flora of the juniper swajnp 



