18 PROCEEDINGS OF THE NATIONAL MUSEl I/. fol. 38. 



The following year BisChof a stated that sandstone cemented by 

 barium sulphate occurs at Munzenberg, in the Wetterau district of 

 Germany; and that in the district of Kreuznach and near Leipzig, 

 Germany, and in the vicinity of Bologna, Italy, are found globular 

 concretions composed of sand, barite, and some clay. 



In 1868 Laspeyres, 6 in discussing the wells near Durkheim, in 

 Bavaria, Germany, said that baritic sandstone had been encountered 

 in a bore hole at depths of 330 and 820 feet. 



In 1883 Zittel'' reported that, during an exploration of the Lybian 

 Desert of northeastern Africa, he had gathered rounded and slightly 

 flattened sand-barite concretions from the isolated mountain of Gella 

 Stiui, between Bauite and I lass. 



In 1889 Clowes d announced that some of the Triassic sandstones 

 near Nottingham, England, are cemented with 33 to 50 per cent 

 barium sulphate. He directed attention in particular to a sand- 

 stone pillar, some 30 feet in height and 70 feet in circumference, 

 which is crowned by a flattened mushroom-like cap of baritic sand- 

 stone. 



In 1897 Polak ( described crystals of barite from a railroad cut 

 near Tetschen-Bodenbach, Bohemia, and said that some of these 

 contain included quartz grains. 



The year following, Moore ' added another locality, near Bidston 

 Hill, in the Triassic of England. There the barite is present in 

 quantities up to 34 per cent as a cement in globular sand concretions, 

 the size of walnuts, which weather out from the sandstone. 



In 189'.) Clowes" referred to his previous communication, and 

 stated further that barium sulphate is not rare among the Triassic 

 sandstones of England. The same year, Wedd h mentioned the pres- 

 ence of baritic sandstone in North Staffordshire. 



«(i. Bischof, Chemical and Physical (.Jeolo^y, vol. I. L854, p. !:i:>. 



''II. Laspeyres, Kreuznach und Durkheim a. d. Mardt. Zeitschr. Deutsch. 

 Geol. Ges., vol. 20, 1868, p. 174. 



c K. A. Zittel, Beitrage zur geologie der Libyschen Wiiste. Palaeontographica, 

 vol. :50, 1883, p. I J I. 



<*F. Clowes, Barium sulphate as a cement: in sandstone. Proc. Roy. Soc, vol. 

 46, 1880, pp. 363 368. 



e J. M. Polak, Oebe'r Baryl krystalle von der Bohemia bei Tetschen-Bodenbach. 

 Sitzungsb. Deutsch. Nat. Med. Ver. Lotos. Prague, vol. 17, L897, pp. 78 80. 



.'('. C. Moon-, The Chemical examination of Bandstone from Prenton Mill and 

 Bidston Mill. Proc. Liverpool Geol. Soc., vol. 8, 1898, pp. 241-267. Especially pp. 

 266-267. 



o V. Clowes, Deposition of kirium Bulphate as a cementing material in sandstone. 

 Proc. Roy. Soc, vol. 64, L899, pp. 374 :?77. 



&C. B. Wedd, Note on barium sulphate in the Bunter sandstone of North Stafford- 

 shire. Geol. Mag., vol. 6, 1899, p. 508. 



