CHEMICAL METHODS 963 



2,198,619 Issued April 30, 1940. Leo Horvitz. "Geochemical Exploration." 



2,210,546 Issued August 6, 1940. Gerald L. Hassler. "Soil Gas Sampling Device 



and Method." 

 2,212,211 Issued August 20, 1940. August H. Pfund. "Apparatus for Detecting and 



Measuring Heteroatomic Gases." 

 2,212,681 Issued Aug. 27, 1940. Thomas H. Dunn. "Soil Gas Analysis." 

 2,213,138 Issued Aug. 27, 1940. John T. Hayward. "Method and Apparatus for 



Detecting Oil in Well Drilling." 



2.213.904 Issued Sept. 3, 1940. Thomas H. Dunn. "Geochemical Prospecting." 



2.213.905 Issued Sept. 3, 1940. Joseph Baldwin Clark. "Geochemical Prospecting." 

 2,219,540 Issued Oct. 29, 1940. Benjamin Miller. "Gas Analysis Method and 



Apparatus." 

 2,223,183 Issued Nov. 26, 1940. Edward B. Peck. "Prospecting for Oil." 

 2,223,785 Issued Dec. 3, 1940. Gerald L. Hassler. "Gas Sampling System." 

 2,227,438 Issued Jan. 7, 1941. John G. Campbell. "Method of Determining the 



Petroleum Oil Content of Earth Samples." 

 2,228,223 Issued Jan. 7, 1941. George S. Bays. "Geochemical Prospecting." 

 2,229,884 Issued Jan. 28, 1941. Curtis R. Chalkley. "Oil and Gas Detector Apparatus." 

 2,230,593 Issued Feb. 4, 1941. Gerald L. Hassler. "Apparatus for Analyzing Gaseous 



Mixtures." 

 2,234,637 Issued March 11, 1941. Millard S. Taggart, Jr. "Oil Prospecting Method." 

 2,241,154 Issued May 6, 1941. Jacob Neufeld. "Well Surveying Method and 



Apparatus." 

 2,257,170 Issued Sept. 30, 1941. Lynn G. Howell. "Method for Locating Hydro- 

 carbon Deposits in the Earth." 

 2,261,498 Issued Nov. 4, 1941. John C. Karcher. "Apparatus for Analyzing Gases." 

 2,261,764 Issued Nov. 4, 1941. Leo Horvitz. "Geochemical Prospecting." 

 2,266,556 Issued Dec. 16, 1941. Walter A. Kelly. "Method of Locating Oil Deposits." 

 2,269,889 Issued Jan. 13, 1942. Ludwig W. Blau. "Process for Locating Valuable 

 Subterranean Deposits." 



2.270.299 Issued Jan. 20, 1942. Leo Horvitz. ''Geochemical Prospecting." 

 2,272,645 Issued Feb. 10, 1942. Esme E. Rosaire. "Geochemical Prospecting." 

 2,278,929 Issued April 7, 1942. Leo Horvitz. "Geochemical Prospecting." 



2,283,650 Issued May 19, 1942. Charles M. Sanborn. "Earth Sampling Equipment." 

 2,284,147 Issued May 26, 1942. Henry N. Herrick. "Alethod and Apparatus for Soil 



Gas Analysis." 

 2,286,384 Issued June 16, 1942. Robert Thomas Sanderson. "Apparatus for Gas 



Analysis." 

 2,287,059 Issued June 23, 1942. Ralph N. Platts. "Apparatus for Obtaining Soil 



Samples." 

 2,287,101 Issued June 23, 1942. Leo Horvitz. "Means and Method for Analysis." 

 2,289,687 Issued July 14, 1942. R. W. Stuart. "Method and Apparatus for Logging 



Wells." 



2.292.300 Issued Aug. 4, 1942. Robert O. Smith. "Photochemical Exploration Method." 

 2,294,425 Issued Sept. 1, 1942. Robert Thomas Sanderson. "Geo-Micro-Biological 



Prospecting." 

 2,297,939 Issued Oct. 6, 1942. John G. Campbell. "Method of Detecting the Pene- 

 tration of an Oil-Bearing Horizon." 

 2,305,082 Issued Dec. 15, 1942. Claude R. Hocott. "Geochemical Prospecting." 

 2,305,384 Issued Dec. 15, 1942. Herbert Hoover, Jr. "Geophysical Prospecting Method." 

 2,310,291 Issued Feb. 9, 1943. Leo Horvitz. "Geochemical Prospecting." 

 2,310,318 Issued Feb. 9, 1943. Esme E. Rosaire. "Geochemical Prospecting." 

 2,311,151 Issued Feb. 16, 1943. John G. Campbell. "Analysis of Soil Samples for 



Determining Oil Content." 

 2,312,271 Issued Feb. 23, 1943. Robert O. Smith. "Method of Locating Subterranean 



Petroleum Deposits." 

 2,318,062 Issued May 4, 1943. Trent R. Dames. "Soil Sampler." 

 2,320,577 Issued June 1, 1943. Thomas H. Dunn. "Geochemical Prospecting." 

 2,319,734 Issued May 18, 1943. Leo Horvitz. "Geochemical Prospecting." 

 2,320,681 Issued June 1, 1943. Hubert H. Thompson. "Alethod of Analyzing Earth 



Formations." 

 2,321,293 Issued June 8, 1943. Gerald L. Hassler. "Apparatus for Measuring Pres- 

 sures in Containers." 



