398 L. D. Burling — Protichnites and Climactichnites. 



34. It should be noted that these "forward-curving transverse furrows" 



are more or less sinuous and bend sharply backward (using the 

 same terminology) at their union with the sides of the trail, which 

 they join at a tangent. Consideration of this one trail alone (pi. 39, 

 fig 2 of Walcott) seems sufficient to prove that the animal must 

 have progressed in a direction exactly opposite to that assumed by 

 Walcott. Under the new interpretation the transverse furrows 

 bend sharply forward at the sides and are bent backward in the 

 center, and are closely covered by the series of curved raised lines 

 left by the posterior margin of the animal (see cj of text). 



35. Cambridge Nat. Hist., vol. iv, Crustacea and Arachnids, fig. 157, p. 



274. 



36. Proc. Amer. Acad. Sci., vol. xxxvi, p. 66, 1900. 



37. Science, n. ser., vol. viii, p. 382, 1908. 



37a. Bull. Geol. Soc. America, vol. xxiv, 1913, pp. 463-464. 



38. Trans. Wisconsin Acad. Sci., vol. v, pp. 278-279, 1882. 



39. Bull. New York State iAius., No. 69, fig. 1, p. 961. 1903. 



40. Smithsonian Misc. Coll., vol. Ivii, pi. 38, 1912. 



41. See Bull. New York State Mus., No. 80. 1905, pi. 3. 



42. Science, n. ser., vol. xxviii, p. 382, 1908. 



43. Bull. New York State Mus., No. 80, pi. 3, 1905. 



44. Science, n. ser., vol. xxviii, p. 382, 1908. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. A New Method for ike Recovery of Salts of Potassium and 

 Aluminium from Mineral Silicates. — Many efforts have been made 

 to devise methods for extracting potassium from orthoclase feld- 

 spar which occurs in such quantity and purity as to make it a 

 possible source of supply for salts of this element, and the desir- 

 ability of such a process has greatly increased since the time 

 that the supply of German potash salts has been cut off. The 

 methods heretofore proposed for this purpose do not appear to 

 have been successful on the large scale. J. C. W. Frazer, W. "W. 

 Holland and E. Miller, of Johns Hopkins University, have now 

 proposed for the purpose a method which appears unusually 

 promising, since comparatively low temperatures are required 

 for the operation, and since, besides the potassium, the aluminium 

 of the mineral may be extracted in the process. The finely 

 ground feldspar is mixed with about 0.8 parts of potassium 

 hydroxide (or an equivalent amount of the sodium compound) 

 and heated for about an hour at a temperature of 275 to 300° C. 

 A reaction takes place whereby practically one-third of the silica 

 of the feldspar is converted into potassium silicate, soluble in 

 water, while the residue corresponds in composition to the min- 

 eral leucite : 



KAlSigOg + 2K0H = KAlSi.Oe + K^SiOg + H^O 



