Reviews — Rock Salt. 279 



As far as I have been able to discover, the majority of the English 

 geologists at the present time wish the term Ordovician to be generally 

 adopted. And so do I, We are also of one mind that, if the term 

 Lower Silurian is to be rejected, the term Upper Silurian must also be 

 given up. But when the proposal is made to substitute for the latter 

 the term * Silurian' simply, then I think a false move has been taken, 

 which may lead to confusion not only abroad but also in England. 

 Even if Murchison's term, Silurian, was originally applied to only the 

 upper part of the formations in question, it must not be forgotten that 

 it was created earlier than the term Cambrian, and that also Llandeilo 

 was included in it. Murchison's term, Silurian, has consequently 

 never coincided with what would now be called by that name. And 

 lastly, as we know, he let the name embrace all the strata from the 

 base of the Cambrian up to the base of the Devonian. In this 

 comprehensiveness the name Silurian, especially through Barrande's 

 influence, has also come to be used throughout the world. 



To use the name Silurian in the significance that English geologists 

 have of late attempted is, as I have shown above, not justified, as well 

 as very misleading. To discard it entirely is quite unfeasible ; not 

 only would it be an act of great injustice towards the renowned author 

 of the Silurian System, but it would be an injustice that would 

 assuredly bring its own punishment. 



Since, then, the term Silurian mud be used, it seems to me that 

 nothing else is possible but to take it in the sense Murchison ultimately 

 gave it, which, through Ban-ande's influence, has won favour every- 

 where. If the name Ordovician is introduced, the name Silurian, 

 as far as I can see, must be used as a collective name, and the so-called 

 Upper Silurian receive a fresh name. And as such, de Lapparent's 

 * Grothlandien ' (Gotlandium) would certainly be suitable. 



E, E ^V I E -V^ S. 



I. — Rock Salt: its Origin, Geological Occubrences, and Economic 

 Importance in the State of Louisiana ; together with Bbief 

 Notes and References to all known Salt Deposits and Indus- 

 tries of the World. By G. D. Harris, assisted by C. J. Maury 

 and L. Reinecke. Bulletin No. 7 of the Geological Survey of 

 Louisiana, 1908. pp. 259, with 21 text-figures and 48 plates of 

 maps, sections, and views. 



THE ' salines ' of North Louisiana were known to the Indians 

 before the advent of the white man, and they used to resort to 

 those places to obtain their salt. The position of the ' salines' is 

 indicated by the ' licks ', where vegetation is prevented from growing, 

 over patches several yards square, by the licking of the ground by 

 cattle. 1 Their presence is further indicated by brine-springs which 

 issue along the beds of streams, and by the sinking of wells. Brine 



1 The "Big Bone Lick ", Kentucky, and others of a similar kind were well known 

 to the early geologists by the discovery of abundance of remains of the Mastodon and 

 other extinct mammals who came down to lick the salt in prehistoric times. Many 

 arrow-heads of stone have been found, showing that the Indians also frequented these 

 salines, probably to shoot big game which came there for salt as well as themselves. 



