694 



SCIENCE. 



LN. S. Vol. XVII. No. 435. 



California oil does not contain tlie series 

 C„H,^^3 so far. as known, but contains tlie 

 other series mentioned. 



Canadian oil contains all the series men- 

 tioned, with larger proportions of the series 

 poor in hydrogen. 



All petroleums contain compounds of 

 oxygen, nitrogen and sulphur, but in vari- 

 able amounts, very small in Pennsylvania 

 oil, large in California, Ohio and Canadian 

 crude oils. 



A summary of what is known concerning 

 the origin of petroleum was given, with 

 some suggestions based on recent knowl- 

 edge of its general composition. 



SATURDAY, APRIL 4. 



Morning Session, 10 o'clock. 

 President Smith in the chair. 



A Further Classification of Economies: 



Professor Lindley Miller Keasbey, of 



Bryn Mawr, Pa. 



An economy is a system of activity 

 whereby the utilities inherent in environ- 

 ment are, through utilization, converted 

 into actual utilities. 



These economies can be distinguished 

 from one another in two ways: First, ac- 

 cording to the motive making for utiliza- 

 tion, and, second, in accordance to the 

 means employed in the process. They may 

 be classified as the automatic, characteristic 

 of plants; the instinctive, characteristic of 

 animals; the rational, characteristic of hu- 

 man life. 



The rational economy may be subdivided 

 into the natural, characteristic of savages: 

 the proprietary, characteristic of barbar- 

 ians; and the commercial, characteristic of 

 western civilization. 



Some Features of the Supernatural as Rep- 

 resented in Elizabethan and Jacobean 

 Plays: Professor Felix B. Schelling, 

 of Philadelphia. 



The Hamites and Semites in the Tenth 

 Chapter of Genesis: Professor Morris 

 Jastrow, Jr., of Philadelphia. 



The Most Insidious Cause of Error in 

 Quantitative Chemical Research: Pro- 

 fessor Theodore W. Richards, of Cam- 

 bridge, Mass. 



Experiments are recorded and quoted 

 showing that most if not all crystals de- 

 posited from solutions contain included 

 mother liquor. The experiments show also 

 that before this mother liquor can be elimi- 

 nated by pulverization, the absorption of 

 water from a moist atmosphere begins to 

 augment appreciably the weight of the sub- 

 stance. It is pointed out that this absorp- 

 tion can not be overcome in the case of 

 hydrated salts without a loss of water of 

 crystallization also. Hence' hydrated salts 

 can not be accurately weighed according to 

 any usual procedure. In the case of anhy- 

 drous salts the elimination of absorption is 

 easy, but in order to remove included water 

 the cell walls enclosing it must be disin- 

 tegrated. Mechanical, thermal and chemi- 

 cal methods of such disintegration are 

 classified and applied to the preparation of 

 pure materials. It is pointed out that other 

 impurities are usually included with the 

 solvent in the invisible cells, and that these 

 other impurities must never be forgotten in 

 the course of the further purification. 

 Finally, it is suggested that these almost 

 infinitesimal enclosed impurities might be 

 used as a clue to the manner of growth of 

 natural minerals, and hence to the mechan- 

 ism of geophysical processes. 



The Warfare against Tubercidosis: Dr. 



Mazyck p. Ravenel, of Philadelphia. 



All efforts at the eradication of tuber- 

 culosis to be successful must be based on 

 the fundamental fact of its communica- 

 bility, and in the main it is to be treated 

 as the other contagious diseases, though 

 the restrictions need not be so severe. 



