Decemdeb 17, 1009] 



SCIENCE 



893 



Conard fissure. Rangifer is stated by Osborn 

 on page 86 as not appearing in the mid-Pleis- 

 tocene, but on page 87 as coming in late. 

 According to Shaler, R. tarandus seems to 

 have been abundant in the older deposits of 

 Big Bone Lick and a species of caribou has 

 been found at Muscatine, Iowa. The late 

 mid-Pleistocene age of the part of the loess 

 containing the Rangifer bones is yet to be 

 proved. Ursus is a third genus said by Pro- 

 fessor Osborn to be a late comer in glacial 

 times. One or two species of the genus were 

 reported from Port Kennedy cave. Two spe- 

 cies of the genus, one not distinguishable by 

 Dr. Leidy from the common black bear, were 

 found near Natchez, Miss., in the loess. 

 Shimek, who has made a special study of the 

 loess at Natchez,' says that " the solid blue 

 clay," in which the vertebrates of that section 

 have been found, probably does not belong to 

 the loess, but is older still. How old it is no 

 one knows. 



According to the table cited above, the two 

 species of mammoth, Elephas columhi and E. 

 primigenius, disappeared during the mid- 

 Pleistocene, while the mastodon perished 

 during the " upper mid-Pleistocene." Now, 

 northwestern Ohio, northern Indiana and 

 southern Michigan are deeply covered over 

 by a thick mantle of drift materials that was 

 deposited by the Late Wisconsin ice sheet, the 

 very last of the glacial advances. In depres- 

 sions left on the surface after the retreat of 

 this sheet there were formed lakes and ponds 

 that afterwards became more or less com- 

 pletely filled up, forming marshes, peat bogs 

 and swales. In ditching such places there 

 have frequently been found the teeth and 

 bones, sometimes nearly complete skeletons of 

 the two elephants and of the mastodon. The 

 fine specimen of E. columhi, now in the Amer- 

 ican Museum at New York and described by 

 Professor Osborn, was found in just such a 

 situation. It would be very difficult to prove 

 that the mastodon survived the mammoth. It 

 is certain that both the elephants and the mas- 

 todon continued to inhabit the Mississippi 

 Valley long after the glaciers had abandoned 

 the region and therefore during at least a 



'Bull. Lab. Xat. Hist., Iowa Univ., V., p. 307. 



part, if not the whole, of the Postglacial stage 

 of the Pleistocene. 



Oliver P. Hay 



C.\T.\LYTIC ACTION OF IRON SALTS 



GiBBs' has shown that the red coloration of 

 phenol is due to oxidation brought about by 

 the catalytic action of sunlight. The oxida- 

 tion products condense and form red sub- 

 stances, as for example, phenoquinone. 



As Dr. Fenton has shown that oxygen and 

 sunlight are equivalent to hydrogen peroxide 

 and a trace of a ferrous salt in their oxidizing 

 action upon organic compounds, it struck me 

 that the catalytic action of iron might be 

 studied colorimetrically by resource of Gibb's 

 work. 



A concentrated solution of phenol in ben- 

 zene was divided into three equal parts. The 

 first was exposed to sunlight for two days, the 

 second was treated with a small quantity of 

 hydrogen peroxide, and to the third were 

 added a trace of ferrous sulphate, and then 

 the same quantity of hydrogen peroxide as 

 was added in the second case. 



No change could be seen in the first, the 

 second almost immediately developed a very 

 slight pink coloration, but the third at once 

 changed to a reddish-brown color. 



Blank experiments were made to show that 

 the color was not due to benzene. Again, in 

 order to prove that the color was not due to 

 the iron alone, traces of a ferrous and a ferric 

 salt were added to a similar benzene solution 

 (without the hydrogen peroxide) when a green- 

 ish color was produced, which in no way 

 could be associated with the reddish-brown 

 color caused by iron and peroxide. 



Further experiments showed that by means 

 of the above reagents many of the laws of 

 catalysis could be actually demonstrated to a 

 large class in a lecture. More especially be- 

 cause the action was rapid and could be fol- 

 lowed by the production of color. For ex- 

 ample, to prove in a rough manner that 

 catalysis can not affect the final equilibrium, 

 the two differently colored solutions (one 

 containing traces of iron and the other not) 



' Philipp. J. Sci., 1909, 4, 133. 



