690 General Notes. [August, 



bottom to the surface of the solution. The tube is at first thin, 

 but constantly grows in thickness by the deposition of silica on 

 the outside, thus forming a series of bands. The authors suggest 

 that natural agates are formed by a somewhat similar chemical 

 process. By introducing oxide of iron in the solution, they have 

 closely imitated certain jaspers and moss agates. 



Description of the Geological Map of Sutherland. — Professor 

 Heddle describes a map published in a former number. 



Specular Iron in a Copper Works Slag.—W. Terrill has found 

 hexagonal plates of specular iron in a copper works slag. . 



Lernilite, and other supposed new German minerals.— In 

 a recent paper by Schrauf in the Zeitschrift fur Kry stall o^rapluc, 

 etc., upon the magnesian silicates of Southern Bohemia, a number 

 of new names are proposed for various substances allied to ser- 

 pentine, most of which are products of alteration. Every miner- 

 alogist knows the numerous substances found with serpentine in 

 a more or less altered condition, but every one will regret that 

 Professor Schrauf has thought it necessary to give distinctive 

 names to these substances. Superfluous names, if retained in the 

 science, will cause determinative mineralogy to become burden- 

 some. Enophite, lernilite, kelyphite, siliciophite, berlauite, 

 schuchardite, hydrobiotite, parachlorite, and protochlorite are 

 the names here introduced to designate substances most of which 

 are already well known under more simple designations. 



A curious mistake is made in the name " lernilite." This is 

 the name he applies to the vermiculite of Lenni, Delaware 

 county, Pa., already described by Professor Cooke. The name 

 Lenni having been misspelt in Professor Cooke's paper, the error 

 is perpetuated by Schrauf in his " lernilite." As the term "len- 

 nilite" has already been appropriated for a variety of orthoclase 

 from the same locality. Professor Schrauf must find another 

 ■ name for the mineral. " Hydrobiotite " is also a term previously 



Mineralogical Notes.— F. W. Clarke and N. W. Perry in i;he 

 American Chemical Journal for June describe a massive purple 

 mineral from Colorado, which appears to be a decomposed fluor 

 spar mixed with calcite. An analysis is given, and the name 

 "gitwiisonitc" is proposed. Certainly no cause has been shown 

 for assigning this new name to an impure and partially studied sub- 

 stance. According to Dr. Heddle. a schist containing andaui- 



site crystals is used in Scotland for millstones. The hard crystals 

 protrude from the surface of the stone and act as grinding teeth. 

 Dr. M. E. Wadsworth has found picotite, a chrome spinel, in »J= 



basalt of Mt. Shasta, California. The Smithsonian Report: 



for 1880, contains an excellent summary of recent mineralogical 



discovery, prepared by the late George W. Hawes. ■ u - 



Derby in a recent number of the American Journal of Science, 



