Maech 3, 1899.] 



8CIENGE. 



335 



prepared for the next session of Congress in 

 December. 



The following papers were read : 



' Eecent Extension of Our Knowledge Regarding 

 Nitrates as Plant Food,' Dr. J. A. Myers. 



' A Method for the Analysis of Canned Condensed 

 Milk,' F. S. Hyde. 



' Manufacture of Ether,' Alfred Roos. 



' Manufacture of a New Guaicol Compound,' L. 11. 

 Renter. ^ 



' Explosibility of Nitrogen Iodide and Acetylene 

 Copper Compounds and Use of the Latter in Manufac- 

 ture of Alcohol and Ether, ' L. H. Renter. 



'Chemistry of the Dynamite Process of Weighting 

 Silk, ' Rafael Granja. 



' Chemistry of the Yelooitan Process — Quick Tan- 

 ning, ' Rafael Granja. 



' Melting Point as a Cyclic Function,' Thos. Bayley, 

 England. Read by title. 



DuEAND Woodman, 



Secretary. 



GEOLOGICAL CONFERENCE AND STUDENTS' CLUB 

 OF HARVARD UNIVERSITY. 



Oeological Conference, January 10, 1899. — 

 Dr. T. A. Jaggar, Jr. gave a communication on 

 'The Geology of the Northern Black Hills,' 

 and illustrated it with many lantern views, 

 photographs and specimens. He dwelt espe- 

 cially on certain facts, discovered by him dur- 

 ing the past summer, which throw new light on 

 the general problem of intrusives. These will 

 be published in full later. 



Students' Oeological Club, January 17, 1899. — 

 In a paper entitled ' Our Present Knowledge 

 ■of the Geology of the Boston Basin,' Mr. R. E. 

 Burke briefly summarized the literature on the 

 geology of that area. 



Geological Conference, January 24, 1899. — Mr. 

 H. T. Burr presented some results obtained in 

 mapping the conglomerates of the Boston Area 

 ■with a view to determining their relative age. 

 The Commonwealth Avenue cut in the Roxbury 

 conglomerate shows a series which strikes 

 transversely (E-W) to similar, adjoining con- 

 glomerates to the north and south. Evidence 

 was offered to show that this structure is due to 

 overthrusting from the north followed by 

 normal faulting. 



The Brighton amygdaloids have generally 

 been considered as flows. The speaker held, 



after a detailed study of their contacts, that 

 these rocks are intrusive. Further, their injec- 

 tion was probably preceded by faulting. 



In discussing this paper, Professor Shaler 

 favored the division of the Roxbury conglomer- 

 ates into formations, on the basis of recognized 

 periods of denudation that alternated with 

 periods of deposition. 



Mr. Robert DeC. "Ward spoke on ' Acclimati- 

 zation of the White Man in the Tropics.' By 

 acclimatization is meant adaptation to a new 

 climate. This problem, although an old one 

 for Europeans, has confronted us for only a few 

 months. It arises as a result of physiological 

 changes that take place in the body, and may 

 be best studied from two points of view, (1) a 

 consideration of these physiological changes, 

 and (2) a study of the diseases most prevalent 

 in the tropics which a resident there is most 

 likely to contract. 



In connection with the former part of the 

 problem the chief factors are heat and humidity. 

 Heat, in itself, is not dangerous ; but it becomes 

 so when significant humidity is added. Heat 

 induces evaporation and thus greater desire for 

 drink. Accordingly, considering a certain in- 

 crease in drink necessary, those nations which 

 drink hard liquor will suffer more than those 

 which use wine. Cereals afford safer food than 

 meats. 'In regard, then, to both liquid and 

 solid food the southern Europeans have ad- 

 vantages over the English. Too much or too 

 little exercise is extremely dangerous ; a certain 

 amount is absolutely necessary. The most 

 healthy tropical districts are high and dry. 



In connection with the latter part of the prob- 

 lem, three diseases are especially prevalent, 

 namely, sunstroke, yellow fever and malaria. 

 Sunstroke is chiefly influenced by the rains. 

 Malaria, the greatest obstacle in acclimatization, 

 comes with the rains, but is also closely related 

 to soil conditions. Yellow fever, although vary- 

 ing with the rainy season, finds its check in ele- 

 vation. Thus, in the respective countries, the 

 following altitudes have been found to be about 

 the upper limit of that disease : in the United 

 States, 800 feet ; in Mexico, 2,300 feet ; in Bra- 

 zil, 2,700 feet ; and in Jamaica, 4,000 feet. 



The chief physiological changes resulting from 

 life in the tropics are increased respiration and 



