APPENDIX D. GEOLOGY. 153 



tion showing vessels of the shape of a half or gibbous moon. This fact 

 shows that the climate was warm enough for trees analogous to the 

 palm tribe to flourish ; yet the great predominance of dicotyledonous 

 forms shows a close analogy with the existing vegetation of the south- 

 ern part of our country ; nor is there evidence, in these specimens, of a 

 temperature above that now existing in our southern States, since seve- 

 ral species of palms occur there. 



The two subsoils analyzed by Professor Shepard, give very interesting 

 results. The first is highly calcareous ; and when the lime shall have 

 been exhausted in the overlying soil, this material, thrown up by sub- 

 soil ploughing, would be equal to a large dressing of lime. In the 

 other subsoil we have an extraordinary amount of sulphate of lime, and 

 a sufficiency of carbonate of lime, as well as chlorine and soda. It 

 seems hardly possible to doubt that such a basis would need only 

 organic matter to render it one of the most productive of all soils ; and 

 when we think how extensive the gypsum formation is from which this 

 subsoil was obtained, we cannot but anticipate (unless there are coun- 

 teracting causes of which I am ignorant) that that portion of our coun- 

 try will become a rich agricultural district — I mean the region lying 

 east of the " Llano estacado." 



Only one specimen of common salt (chloride of sodium) was sent 

 among the specimens, and that, as you inform me, " was procured by 

 the Comanche Indians in the country lying between the Canadian and 

 Arkansas rivers." 



We are now prepared to appreciate an analysis of the ^ater of Red 

 river, which has been executed in the laboratory of Amherst College by 

 Mr. Daniel Putnam, under the direction of Professor W. S. Clark. 

 This is somewhat of a mineral water, and you remark that all the waters 

 originating in the gypsum formation have the same bitter and nauseat- 

 ing taste. I think you are right in the opinion that the ingredients 

 are derived from that formation. Analysis shows that the taste depends 

 upon the presence of three salts in nearly equal proportions, two of which, 

 sulphate of magnesia, or Epsom salts, and chloride of sodium, are very 

 sapid. Mr. Putnam's analysis is as follows : 



" Water from Eed river — 



Water in fluid ounces 4. 



Weight of water in grammes 127.800 



Weight of chlorine present .051 



Weight of lime present .033 



Weight of sulphuric acid present .095 



Eesidue evaporated to dryness, and weighed, proba- 

 bly, sulphates of soda and magnesia together, 

 weight 168 



