522 



NATURE 



[September 25, 1850 



to coincide with the Tertiary period, is pushed back 

 farther and farther into the Secondary ; a flora in the 

 United States, otherwise Jurassic in facies, containing no 

 less than seventy-five species, or more than 20 per cent, of 

 Phanerogams, according to Lester Ward. In England 

 the mysterious Wealden, which from analogy should 

 preserve rich fossil floras shedding light on the origin of 

 Angiosperms, yields little but tubers and stems of Equi- 

 setura, scraps of ferns and conifers, and a unique liliaceous 

 stem ; while our Greensands, Gault, and Chalk afford 

 little or nothing from which the existence of flowering 

 plants during their deposition could be inferred. The 

 veil which has proved absolutely impenetrable in our 

 country, and has so long enshrouded the dawn of dicotyle- 

 donous vegetation, seems, however, about to be lifted, 

 and we wait with the utmost interest the publication of 

 the infra-Cretaceous floras of the Potomac by Prof. Fon- 

 taine, and of the oldest European Dicotyledons, from the 

 beds of Gault age in Portugal, by Saporta. Though, 

 however, the forms will be revealed, a long time must 

 probably elapse before we can hope to rightly interpret 

 them, J. Starkie Gardner. 



ON THE INFLUENCE OF HEAT ON COPPER 

 POTASSIUM CHLORIDE AND ITS SATU- 

 RATED SOLUTION.^ 



'X'HE blue crystals of copper potassium chloride, 

 -*■ CuCl2.2KCl.2H2O, when heated to upwards of 100°, 

 change their colour, and a closer investigation proves 

 such is due to the formation of a new brown salt, 

 CuClg.KCl, according to the equation — 



CuCI2.2KCl.2H2O = CuCla-KCl + KCl + 2H2O. 



This same new substance can be obtained at lower 

 temperatures, on heating the blue double salt in presence 

 of copper chloride ; it then results according to the 

 following symbols — 



CuCl2.2KCl.2H2O + CUCI2.2H2O = 2CUC12.KC1 + 4H2O. 



Both transformations are reversible — i.e. the primitive 

 substances are obtained anew on cooling, and both take 

 place at definite temperatures, 93° and 56° respectively, 

 which temperatures can be accurately determined in 

 studying the abrupt change of volume which accompanies 

 that of chemical composition. 



The temperatures of 56^ and 93° are, moreover, charac- 

 terized by an intersection of three curves of solubility in 

 each case, viz.— 



1. At 56° the following three will meet — 



{a) That of the system CuCI2.2KCl.2H2O ; CUCI2.2H2O. 



[b) That of the system CuCL,.2KC1.2H20 ; CuClg.KCl. 

 {c) That of the system CuCla KCl ; CUCI2.2H2O. 



2. At 93° — 



{a) That of the system CuCl2.2KCl.2H2O ; CIK. 



{b) That of the system CuCl2.2KCl.2H2O ; CuCL.KCl. 



(c) That of the system CuClsKCl ; CIK. 



Lastly, those same temperatures are characterized also 

 by an intersection of four vapour pressure lines at each, 

 viz. — 



1. At 56° those of the above-mentioned three saturated 

 solutions, and that of the dry blue salt, mixed with copper 

 chloride, meet. 



2. At 93° those of the other three mentioned above 

 and that of the dry blue salt, mixed with potassium 

 chloride. J. H. Van't Hoff. 



^ Abstract of a paper read at the Leeds meeting of the British Ajsociation. 

 NO. 1 09 1, VOL. 42] 



THOMAS CARNELLEY. 



B' 



Y the death of Prof. Carnelley the science of che- 

 mistry in this country has suffered an irreparable 

 loss. It appears that some little time ago Dr. Carnelley 

 had been suffering from an attack of influenza, and it was 

 whilst returning to Aberdeen after a journey to the south, 

 made with the object of recruiting his health, that he was 

 seized with sudden and severe illness, which was due, as 

 his medical attendants discovered, to the formation of an 

 internal abscess. Surgical aid proved unavailing, the 

 patient's strength gradually gave way, and Dr. Carnelley 

 passed away at mid-day of August 27, at the compara- 

 tively early age of thirty-eight. 



Prof. Carnelley was a native of Manchester, the son of 

 Mr. William Carnelley, Chairman of the directors of 

 Messrs. Rylands, Limited, of that city. His early educa- 

 tion was received at King's College School, London, and 

 it was during this period, whilst attending the evening 

 classes at King's College, that Carnelley began the study 

 of that science with which he in after life identified him- 

 self. In 1868 he entered the Owens College, Manchester, 

 gaining one of the Dalton Entrance Mathematical Exhi- 

 bitions. During his career as a student, an exceptionally 

 brilliant one, he busied himself not only with the study of 

 the many subjects required of graduates in science of the 

 London University, but found time to devote special 

 attention to his favourite science, and carried out an 

 original investigation on the vanadates of thallium, for 

 which he received in 1872 the Dalton Chemical Scholar- 

 ship. In this year also he obtained the degree of 

 Bachelor of Science of the University of London, gaining 

 at the final examination for this degree marks qualifying 

 for the scholarship in chemistry, in consequence of which 

 he held the Dalton Chemical Scholarship for an addi- 

 tional year. During the next two years he acted as 

 private assistant to Prof. Roscoe, and commenced his 

 career as a teacher by giving lectures in connection with 

 the evening classes of the Owens College. During the 

 year 1874-75 he continued his studies at the University 

 of Bonn under Profs. Kekuld, Zincke, and Wallach ; and 

 on his return to England in 1875 ^^s appointed Demon- 

 strator and Assistant- Lecturer in Chemistry in the Owens 

 College under Prof, Roscoe. During the time that he 

 held this appointment he also acted as Principal of the 

 North Staffordshire School of Science at Hanley, where 

 his teaching proved eminently successful. In 1879 Car- 

 nelley, who had taken the London degree of D.Sc, was 

 appointed to the newly-founded chair of chemistry in the 

 Firth College, Sheffield, and, after three years' successful 

 work in this institution in fitting up the chemical labora- 

 tory and inaugurating the teaching of chemistry in this 

 College, he passed on to the then recently endowed Uni- 

 versity College of Dundee. Here ample means were 

 placed at his disposal, and he had the satisfaction of 

 superintending the erection of a block of buildings in 

 which are located the chemical laboratories, lecture- 

 rooms, &c., which he had designed and carefully planned. 

 Under his guidance the Chemical Department of the 

 Dundee College rapidly developed ; his enthusiasm, his 

 forgetfulness of self, his unstinted energy, and his ability 

 and zeal as a teacher, all combined to make his depart- 

 ment the most important one in the new College and to 

 endear him to his students. Signally successful as was 

 Carnelley's career in Dundee as a professor of chemistry, 

 he also in many other ways conferred lasting benefits on 

 the town and its inhabitants, amongst whom he spent six 

 years, perhaps the most active of his life, and his accept- 

 ance of the appointment to the chair of chemistry at the 

 University of Aberdeen in 1888 caused universal regret 

 in Dundee. 



Amidst his many duties, first at Owens College, then 

 at Firth College, and afterwards at University College, 

 Dundee, where he conducted both day and evening 



