Septembek 11, 1908] 



SCIENCE 



351 



and that ideas of the life activities of plants 

 are among the most valuable in the subject- 

 matter of botany, the case seems fairly com- 

 plete for a course dominated by physiology. 



In mentioning this seeming corollary I 

 would not have it confounded with the prin- 

 ciple which is here advanced. The principle 

 should hold at all events. If a given teacher 

 finds his classes to be most interested and to 

 work hardest in morphology, then morpho- 

 logical problems should claim the laboratory 

 time. The principle is to make any needful 

 sacrifice in order to achieve the main object, 

 to keep the student at his maximum of in- 

 terest and independent effort. 



Charles H. Shaw 



SOCIETIES AND ACADEMIES 



THE NEW YOEK ACADEMT OF SCIENCES, SECTION OF 

 GEOLOGY AND MINERALOGY 



At the regular monthly meeting of February 3, 

 1908, the following program was presented: 



On Determination of Mineral Constitution 

 through Recasting of Analyses: Alexis A. 



JULEEN. 



The results of investigations continued along 

 the line of complex mineral micro-aggregates, 

 brought before the academy at the January meet- 

 ing, were sho^vn in a series of charts. It appears 

 certain in the ease of very complex mineral an- 

 alyses, after giving due weight to the physical 

 characters and origin of the substances, together 

 with the readiness with which these analyses 

 yield to the process of recasting, that many so- 

 called mineral species are in reality very com- 

 plex micro-aggregates. One illustration, taken 

 from the complete paper, which is to be issued 

 in the Annals of the New York Academy of Sci- 

 ences, Vol. XVIII., Part II., No. 3, is here given 

 as a suggestive case. 



Diatantite, from Farniington Sills, Conn.: Mean 



of two analyses by G. W. Hawes. 



Per Cent 



Silica SiOj 33.46 



Alumina Al^Oj 10.96 



Ferric oxide FeoOj 2.56 



Ferrous oxide Feb 24.72 



Manganous oxide MnO .39 



Lime CaO .92 



Magnesia \ . . MgO 16.52 



Soda Na^O .29 



Water H^O 9.96 



Total 99.78 



This is said, by the analyst, to be " a unisilicate 

 of the pyrosclerite group, with the formula, 



(IRs-t- JAi)Si3-t-3H." 



Dana states that the figures " correspond to the 

 formula R,, ( E, ) jSijOsa -f 9aq, which is near to 

 that of pyrosclerite," and also 



"Comp. H,8(FeMg)i.Al4Si„0„, or 



12 ( FeMg) 2AI2O3 gSiOs 9H,0." 



In the recalculation Dr. Julieu assumes for tlie 

 residual pyroxene the same composition as was 

 determined by Hawes for that mineral from an 

 outcrop of diabase in the same region. On this 

 basis the following hypothetical constituents are 

 indicated : 



Per Cent. 



Pyroxene (residual) 6.78 



Enstatite (residual) 10.45 



Prochlorite 54.45 



Ekmanite 16.33 



Deweylite 8.42 



Limonite 2.99 



Perielase (magnesia) 0.36 



It is apparent by making further comparison 

 that diabantite is not identical with diaban- 

 tachronyn, and it is not at all likely that any 

 specimens of either mixture are ever identical. 



The Annual Meeting of the Geological Society of 

 America, Albuquerque, N. M., December 30-31, 

 1901: E. O. Hovey. 

 An aeeoimt of the chief points of interest in 



connection with the meeting was given. 



A Revised Cross-section of the Rondout Valley 

 along the Line of the CatsJcill Aqueduct: 

 Chaeles p. Bekkey. 



Explorations of the Board of Water Supply of 

 New Yorlc City are now almost completed across 

 the Rondout Valley. There are twelve distinct 

 formations of stratified rock involved, all of which 

 will be cut by the projected pressure tunnel. One 

 unconformity in the series separates the Ordo- 

 vieian Hudson River slates from the overlying 

 conglomerates, shales, sandstones and limestones 

 of Silurian and Devonian age. There are three 

 faults of considerable displacement, together with 

 smaller ones and minor foldings. In the eflort 

 to determine the variations of these formations 

 as to thickness, depth from surface, displacements, 

 physical conditions, water content and capacity, 

 the presence of caves or relative solubility, and 

 the position and depth of the buried channels 

 beneath the drift cover, the available figures are 



