1871.] Mr. G. Gore on the Solvent Power of Liquid Cyanogen. 67 



The extinct Phascolomys Mitchelli, indicated by remains brought to 

 England in 1835 by Sir Thomas Mitchell, C.B., the discoverer of the 

 bone-caves of Wellington Valley, Australia, is determined by specimens 

 subsequently obtained by Prof. Alex. M. Thomson and Gerard Krefft, 

 Esq., from the same caves. A second species, distinguished by characters 

 of the nasal bones, is called, after its discoverer, Phascolomys Krefftii. 

 Modifications of the lacrymal, maxillary, and palatal bones in the existing 

 kinds of Wombat are also applied to the determination of the fossils : 

 specimens from the freshwater deposits of Queensland are tbus shown to 

 belong to the species, Phascolomys Mitchelli, originally founded on fossils 

 from the breccia-caves of New South Wales. The author next proceeds 

 to point out the characters of the mandible in existing Wombats available 

 in the determination of extinct species of Phascolomys. On this basis he 

 defines specimens which he provisionally refers to his Phascolomys Krefftii. 

 He then points out the mandibular characters of Phascolomys Mit- 

 chelli, and shows that the existing Phascolomys latifrons was represented 

 by mandibular fossils from the breccia- caves of Wellington Valley. Pro- 

 ceeding next to the description of fossil mandibular remains of the genus 

 Phascolomys, from the freshwater deposits of Queensland, the author 

 defines Phascolomys Thomsoni, Phase, platyrhinus, and Phase, parvus. 

 The latter, seemingly extinct, species is markedly inferior in size to any 

 of the known existing species. An account of the extinct kinds of Wom- 

 bat, exceeding in size the existing species, will be the subject of a succeed- 

 ing communication. The present is illustrated by subjects occupying 

 seven plates and eight woodcuts, all the figures being from nature and of 

 the natural size. 



II. " On the Solvent Power of Liquid Cyanogen." By G. Gore, 

 F.R.S. Received September 1, 1871 . 



In the following experiments a number of stout tubes of refractory 

 glass of the annexed shape were employed. 



FULL SIZED 

 SECTION OF I ( )) 

 CLASS-TUBE.\V^/ 



Each tube was closed atfone end, and had a flanged mouth at the other. 

 The limb A was 1^ inch long, the limb B 2 inches, and C 7 inches. 



In making the experiments, each tube was first filled, to an extent of 

 inches of its length, with highly dried crystals of mercuric cyanide ; a 

 small fragment of asbestus* was then pushed tightly against the end of the 

 cyanide by means of a thin rod of gutta percha, and the bend of the tube 

 cleaned by means of a slender brush. A number of taper plugs of gutta 



* This may be dispensed with if the mercuric cyanide is perfectly dry. 



G 2 



