July 23, 1909] 



SCIENCE 



127 



It is believed that at a certain time unusual 

 softening of the mass by water caused it to give 

 way, and that the greater part of the visible flow 

 descended at one time, in the manner illustrated 

 by mixtures of soil and rock waste which, on a 

 much smaller scale, frequently flow down ravines 

 or mountain slopes as a result of cloudbursts. 



The Slumgullion flow took place before the be- 

 ginning of the present heavy forest growth and 

 after the glaciation which produced the morainal 

 deposits on the adjacent slopes. 



Francois E. Matthes, 



Secretary 



THE ACADEMT OF SCIENCE OF ST. LOUIS 



The academy met at the academy building, 

 3817 Olive St., Monday evening. May 17, 1909. 



Professor W. E. MeCourt, of the department of 

 geology of Washington University, presented an 

 illustrated paper on " Diamonds in Arkansas." 



Professor McCourt first gave a general account 

 of the properties of the diamond, and an account 

 of some of the famous diamonds of history. Then 

 the general commercial occurrences of the diamond 

 were considered — namely, India, Brazil and Af- 

 rica, whence the world's supply of diamonds has 

 largely come. Diamonds have also occurred in 

 the United States, some of them to a size of fifteen 

 carats, but nowhere in very large quantities. 



In 1906, however, diamonds were found derived 

 from a parent rock in Pike County, Arkansas, 

 near the town of Murfreesboro. The presence of 

 the rock in this region, similar to rook in which 

 diamonds were found in Africa, has been known 

 for some time, and the state survey has mapped 

 one of the areas. The igneous rock is a peridotite 

 which has been pushed up through the Carbon- 

 iferous and Cretaceous quartzites and sandstones, 

 and in places is covered by beds of Post-Tertiary 

 and Quaternary formations. But there does not 

 seem to have been any metamorphism accompany- 

 ing the intrusion of this material. This peridotite 

 is dark colored, basic igneous rock which contains 

 olivine, augite, magnetite, mica and perofskite. 

 In some places the rock is exceedingly hard and 

 dense, but in others it has weathered to a yellow- 

 ish and greenish soft material to a depth of from 

 twenty to twenty-five feet. Covering the region to 

 a depth of a foot or so is a black gumbo soil 

 which contains fragments of the hard peridotite 

 and the country rock. 



The work in this region has not been very ex- 

 tensive, but bore holes have been made in several 



places, one reaching to a depth of 205 feet in the 

 hard rock; several companies have located on the 

 area; and stones to the number of about 000 have 

 already been found. The largest stone is six and a 

 half carats. Some have been cut and are valued 

 at $104 a carat. The colors varj', most of them 

 being white, brown and yellow, thougn one blue 

 diamond has been found and several black ones. 



From these indications this area seems to con- 

 tain a mass of rock similar to the rock in South 

 Africa. But as to the number of diamonds which 

 may be found deeper in the peridotite, that, said 

 Professor McCourt, is a question which can only 

 be settled by actual mining and testing. The 

 results which have been shown by the more or 

 less spasmodic exploitation, however, seem to indi- 

 cate a good promise. 



Professor Nipher stated that he had been un- 

 able to finish his work on electrical discharges on 

 account of recent developments. He has found 

 that the electric corpuscles can be focused by 

 means of a fiber of red glass lying on the film of 

 the photographic plate. When the positive and 

 negative terminals of the influence machine are 

 groundeu at diflTerent points, he finds evidence that 

 the corpuscles are discharging from the negative 

 line to surrounding bodies. They are also moving 

 from surrounding bodies to the positive line. This 

 refracting device seems to furnish a way of making 

 further studies on electric fields. 



The following memorial was adopted in mem- 

 ory of Dr. H. Aug. Hunicke, corresponding secre- 

 tary of the academy at the time of his death: 



Dr. Henry August Hunicke, at the time of his 

 death on April 5, 1909, had been a member of the 

 Academy of Science of St. Louis for rather more 

 than twelve years, during five of which he held 

 the office of corresponding secretary. 



His active interest in everything appertaining 

 to the labors of the academy is indicated, not 

 only by his contributions to its scientific pro- 

 ceedings, but also, to an even greater degree, by 

 his active participation in the business of the 

 council, in matters of organization, in the discus- 

 sion of questions of policy and in the promotion 

 of measures designed to broaden the scope or to 

 increase the usefulness of the academy. 



He was an eff'ective speaker, because his out- 

 look and his sympathies were both broad and 

 deep. Although a keen debater, he was uniformly 

 considerate of the feelings of others and never 

 permitted himself to treat his opponent of the 

 moment with anything less than the most perfect 

 courtesy. His spirit was ever helpful, encour- 



