702 



SCIENCE. 



fN. S. Vol. VIII. No. 203. 



distilled water the water was sterilized, and 

 the author concludes that the oxidation of 

 iron takes place in water in the absence of 

 bacteria and other forms of life, and of am- 

 monia and carbon dioxid. As in no case 

 was air vigorously excluded, the author con- 

 cludes that it is as yet an open question 

 whether it is the water or the dissolved 

 oxygen which acts upon the metal. In the 

 second series saline solutions were used, 

 alkalies and alkaline salts being experi- 

 mented with. In general the alkalies pre- 

 vented action on the iron, but many alka- 

 line salts, as potassium carbonate, hydrogen 

 sodium phosphate, sodium meta- and pyro- 

 phosphates and the bicarbonates, do not 

 prevent action. Sodium peroxidhad no ef- 

 fect. Alkaline potassium salts act more 

 strongly on iron than the corresponding 

 sodium compounds. 



In a recent letter to Nature, Sir William 

 Crookes corroborates the observations of 

 Friedlander and Kayser and of Baly, that 

 helium is a constituent of the atmosphere. 

 In examining the more volatile positions 

 from liquid air no difficulty was found in 

 observing the lines of helium. A sample 

 of helium separated by Professor Dewar 

 from Bath gas showed the undoubted pres- 

 ence of neon. The presence of helium in 

 the atmosphere is at variance with the 

 theorj' advanced, that owing to its great 

 molecular velocity any helium in the at- 

 mosphere would escape from the influence 

 of gravitation, unless, indeed, helium is 

 present in space. 



J. L. H. 



BOTANICAL NOTES. 

 THE FLORA OF THE UPPER SUSQUEHANNA. 



Mr. Willard N. Clute has been study- 

 ing the flowering plants and ferns of the 

 region drained by the upper Susquehanna 

 and its tributaries, mainly in southern New 

 York, with a small area in northern Penn- 

 sylvania, and has brought out his results in 



the form of a pretty little book of about 

 170 duodecimo pages. He has not at- 

 tempted to make a phytogeography of the 

 region, but has given us a local list, which 

 the phytogeographer may profitably take, 

 with similar lists of other regions, in at- 

 tempting to present a general view of our 

 flora. The book opens with a short intro- 

 duction, in which there is a little about the 

 topography, geology, rivers and streams, 

 lakes and ponds, bogs and swamps, moun- 

 tains and ravines, elevations, temperature, 

 rainfall, etc., with brief observations upon 

 the characteristics of the flora, the lesser 

 floras, statistics, etc. ISTo less than 1105 

 species are catalogued, a verj' good showing 

 when it is remembered that only Sperma- 

 tophytes and Pteridophytes are included. 



The nomenclature is quite appropriately 

 the modern one, in accordance with the 

 much discussed ' Rochester Rules,' and the 

 families appear to agree with those of En- 

 gler and Prantl's Pflanzenfamilien, but their 

 sequence is that of the Sixth Edition of 

 Gray's Manual, -even to the position of the 

 Gymnosperms, between the Dicotyledons 

 and Monocotyledons. The record of local- 

 ities given with the species will be of 

 much service to the phj'togeographer, for 

 which purpose the citations should have 

 been still more explicit in many cases. The 

 rarer plants fare better in this regard than 

 do those which have a rather wide distri- 

 bution. 



BOMBAY GRASSES. 



There has recently appeared from the 

 government printing press of Bombay, 

 India, an important work on the grasses of 

 the Bombay Presidenc^^, from the hand of 

 the lamented Dr. J. C. Lisboa. The re- 

 gion covered extends along the Arabian 

 Sea, from 14i to 28 degrees of north lati- 

 tude, or about one thousand miles, and from 

 the coast to an irregular interior line dis- 

 tant from one to three hundred miles, and 

 includes nearly two hundred thousand 



