Chemistry and Physics. ^3 



was discovered by Dr. Henry Hicks near St. Davids in "Wales 

 about twenty years ago, and was subsequently found (by Pro- 

 fessor O. Torell?) in Sweden in 1869. 



Through the- kindness of Mr. J. P. Howley, Director of the 

 Geological Survey of Newfoundland, the writer received, a few 

 months ago a box of Cambrian fossils from that Island and 

 among them fragments which appear to belong to this species. 

 Its most important characters are well represented by the pos- 

 terior half of the center piece of the buckler, by the free cheeks, 

 the long cylindrical genal spines and the peculiar hypostome. 

 The outlines and aspect of the parts preserved agree exactly 

 with those of specimens from the Swedish beds figured by G. 

 Linnarsson.* The Newfoundland fossil sent me is not P. 

 Bennetti of Salter, nor is it Green's P. Harlani ; from both it is 

 distinct by the outlines and furrows of the glabella, by the 

 short eyelobe and by the great extension of the facial suture 

 behind the eyelobes. 



A large species of Paradoxides is also found in the Cambrian 

 slates at Saint John, New Brunswick, but the fragments recov- 

 ered are not sufficiently large or perfect to make it clear that it 

 is the species above referred to. This crustacean of the Saint 

 John Group was nearly a foot and a half long (supposing it to 

 have had extended spines next the pygidium like P. Davidis). 



The American examples of P. Davidis occur in a hard black 

 silico-calcareous shale at Highland's Cove, Trinity Bay, New- 

 foundland, in company with species of Agnostus — A. puncluosus 

 Aug., A. Icevigatus Dalm., A. Acadicus Hartt (var. declivis mihi.) 

 These fossils indicate a new horizon in the Paradoxides beds 

 of America somewhat above that of Braintree, or the known 

 horizons of Newfoundland and New Brunswick. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistey and Physics. 



1. On a simplified method of liquefying Oxygen. — It is well 

 known that liquid ethylene, boiling in free air, gives a cold suffi- 

 cient to liquefy oxygen under pressure, only when the latter is 

 suddenly expanded. By evaporating the ethylene in vacuo or by 

 using liquid methane in free air, Cailletet produced the tempera- 

 ture of liquefaction, both of oxygen and nitrogen. Since, how- 

 ever, ethylene is moi'e readily procurable in the liquid form than 

 methane, the author has experimented on the use of this substance 

 evaporated in free air and has succeeded in obtaining by its means 

 a temperature sufficiently low to liquefy oxygen completely. 

 This he effects by hastening the evaporation of the ethylene sim- 



*De Undre Paradoxideslagren, Stockholm, 1883, Plate II. 



