342 



SCIENCE 



[N. S. Vol. XLVI. No. 1188 



that he had to hurry up to push at all? It 

 would seem to me to be true in this case also 

 that the push back on him -would be the same 

 if the cart were in the same state of strain and 

 at rest. 



If the point of view brought forward here 

 is correct it would seem to me desirable to 

 leave out of any elementary discussion of me- 

 chanics an " inertia reaction." 



Elizabeth B. Laird 



Mount Holtoke College 



AN ADDITIONAL NOTE ON "THE OOLITIC 



AND PISOLITIC BARITE FROM THE 



SARATOGA OIL FIELD, TEXAS" 



About three years ago the writer wrote a 

 description of some barite of unusual type 

 from the Saratoga Oil Field, Texas.' Speci- 

 mens of this mineral have been brought to the 

 surface in pumping, and they have been found, 

 in all cases reported to the writer, at a depth 

 around 1,200 feet, indicating that they prob- 

 ably have their source in a definite geological 

 horizon. At the time the above-mentioned 

 paper was written it was supposed that the 

 concretions of this mineral originated with 

 the sands in which they were found but there 

 was no definite information on the subject. 



In discussing this matter a short time ago 

 with Mr. E. G. Woodruff, he stated that at 

 least some of these concretions undoubtedly 

 formed in the wells after they were equipped, 

 because they had been found reaching a quar- 

 ter of an inch in diameter, in a well with a 

 screen on the tubing, the mesh of which was 

 altogether too small to admit a concretion of 

 the size stated. He kindly sent the writer an 

 assortment of specimens of various shapes and 

 sizes from other wells in the same field as 

 those previously described and of approx- 

 imately of the same depth. Tests with the 

 blow-pipe and specific gravity determinations 

 show that the composition of the concretions 

 is almost identical to that of those previously 

 described. A number were examined for 

 nuclei, but in most cases no definite nucleus 

 could be found. Wlien a nucleus is present 



1 Oolitic and Pisolitic Barit« from the Sara- 

 toga Oil Field, Texas," by E. S. Moore, Bull, of 

 the Geol. Soc. of Amer., Vol. 25, pp. 77-79, 1914. 



it consists of earthy material made up mostly 

 of clay and barite and this mass is often 

 stained with iron ioxide which gives the cen- 

 ter of the concentration a brownish tint. 



This additional information is interesting 

 from the standpoint of its bearing on the 

 origin of concretions. It would appear to be 

 practically impossible for bacteria or other 

 low types of life, which are believed to play 

 an important part in the origin of oolites, to 

 exist in a liquid with such strong antiseptic 

 properties as those of warm petroleum con- 

 taining considerable sulphuric acid. It would 

 seem to demonstrate that living organisms 

 are not essenial to the development of oolites 

 and that these may form where precipitation 

 is taking place in an agitated solution, in the 

 absence of life. E. S. Moore 



The Pennsylvania State College, 

 State College, Pa. 



SCIENTIFIC BOOKS 



Ocean Magnetic Ohservations, 1905-1916, and 

 Reports on Special Researches. By L. A. 

 Bauer, Director, with the collaboration of 

 W. J. Peters, J. A. Fleming, J. P. Ault 

 and W. E. G. Swann. Washington, D. C, 

 1917. Carnegie Institution. Pp. vii + 447. 

 This large and handsome volume is the third 

 of the series issued by the department of ter- 

 restrial magnetism of the Carnegie Institution 

 and contains full reports of all the magnetic 

 work of the department at sea during the past 

 eleven years. The two preceding volumes deal 

 with the observations on land for the periods 

 1905-1910 and 1910-1913 respectively. 



In 1905 the wooden brigantine Galilee was 

 chartered at San Erancisco and fitted up for 

 magnetic observations with the purpose of ma- 

 king a preliminary survey of the Pacific Ocean 

 which was at that time " nearly a blanli as re- 

 gards magnetic observations." In the course 

 of three years, this vessel cruised 63,834 nauti- 

 cal miles and, magnetically speaking, put the 

 Pacific Ocean " on the map." In addition to 

 the great number of valuable and accurate ob- 

 servations which were accumulated, these 

 cruises of the Galilee afforded an opportunity 

 for testing and improving magnetic instru- 



