470 Scientific Intelligence. 



shows a most satisfactory continuation and progress of the work 

 of the survey in all its several departments. 



At the close of the report is printed a biographic sketch, by 

 Arnold Hague, of Othniel Charles Marsh, whose recent death 

 interrupted the important investigations in vertebrate paleontol- 

 ogy which he had been carrying on for the Survey, for many 

 years. w. 



2. The Physiography of Acadia ; by Reginald A. Daly. 

 Bull. Museum Comp. Zool., vol. xxxviii; pp. 73-102, 11 plates. — 

 Acadian land forms are shown to consist primarily of two planes 

 of denudation which are essentially subaerial and referable to two 

 cycles of geographic development. The topographic history of 

 the region is believed by Dr. Daly to be closely similar to that 

 of New England and the Southern Appalachians. h. e. g. 



3. Carte Geologique du- Massif du Mont Blanc ; par L. 

 Dttparc et L. Meazec. Comptoir Min. et Geol., Suisse, Geneve. — 

 This map is designed primarily to accompany the work of Duparc 

 and Mrazec on Mount Blanc. The scale is 1/50,000, the relief is 

 very clearly shown, and the glaciers with their morainal materials 

 stand out almost as in a model. The map is a valuable addition 

 to a laboratory outfit. h. e. g. 



4. The mineral constituents of dust and soot from various 

 sources. — A minute spectroscopic investigation has recently been 

 carried on by W. N. Hartley and Hugh Ramage of samples of 

 dust and soot from various sources. These included, for example, 

 the solid matter which fell in a hail storm in April, 1897, at 

 Dublin; similar matter collected in March, 1896; pumice from 

 the Krakatoa eruption of 1883, etc. The examination was 

 extended to sooty matter deposited from the air on the outskirts 

 of Dublin in November, 1897; and also to soot and flue dust 

 obtained direct from gas works and iron furnaces. 



The atmospheric dust from the clouds was found to be some- 

 what regular in composition — each specimen appearing to contain 

 the same proportions of iron, nickel, calcium, copper, potassium, 

 and sodium ; the proportion of carbonaceous matter was small. 

 There was a very considerable difference between the dust from 

 sleet, snow, and hail suddenly precipitated, the difference being 

 in the proportion of lead, which, in the dust from sleet, is much 

 larger than in the other specimens. The dust of November, 

 1897, which fell in a clear, calm night, was uniform in composi- 

 tion ; it was magnetic, and its general similarity to meteorites 

 made it reasonably clear that the material was to be regarded as 

 of cosmic origin. 



The examination of the spectra of specimens of volcanic dust 

 proved that the heavy metals were, without exception, in com- 

 paratively small proportions — lead and iron, for example — while 

 lime, magnesia, and the alkalies were the chief basic constituents. 



Chimney soot from different sources was found to be charac- 

 terized by the small proportion of iron in most specimens and of 

 metals precipitated as hydroxides ; its large proportion of lime 



