MO Linncsan Society, 



Fah. Reau. Cent. Wedp. 



Gold melts 2016 860 1102 



Delft.ware fired 2072 967 1179 40 



Cast-iron melts 2786 1224 1420 



Cream-coloured stone-ware fired 2992 1316 1645 86 



Temperature of the maximum of ex-1 



pansion of platinum, being nearly I ..^^^ ,.,. ,^^r 

 the highest degree of heat attain- [ *^^"" ^^^^ ^^"^ 



able in a laboratory wind-furnace I 



Flint glass furnace, greatest heat ? 3552 1 253 1 956 1 1 4 



Soft iron melts, (according to Clement ~j 



and Desormes, but in all probabi- I qo^c 140^ 9118 

 lity an estimate considerably above | 



the truth). J 



** The still higher temperatures, derived from the experiments of Mr. 

 Wedgwood, which were here given in former editions of the Chemical 

 Catechism, are now omitted ; a comparison of them with the results 

 obtained by Mr. Daniell, by means of his pyrometer, having shown that 

 they cannot be relied upon. Some of the temperatures given in this Table 

 above that of ignition, or 800°, must also be regarded as doubtful, and all 

 of them must be regarded as approximative merely.'' 



Among the additions to the Glossary, we find explanations of the 

 following terms : " Anhydrous, Atmospheres (in a chemical sense). 

 Atom, Capillary Tubes, Cleavage, * Earth's Crust,' Excess, Free 

 (acids, &c.). Hydrous, Isolated State, Isomeric Bodies, Isomorphism, 

 Merorganization, Nascent, Plesiomorphism, Polymeric Bodies, Prox- 

 imate constituents or elements. Real (acids, &c.) Ultimate consti- 

 tuents or elements, Zero, real," &c. &c. 



From a careful review of its contents, we are induced to believe that 

 the new edition of the Chemical Catechism will become as useful a 

 medium of imparting the leading truths of Chemical Science, in its 

 actual state of comparative advancement, as the earlier editions were 

 found to be, in former stages of its progress; — of the justness of 

 this opinion our readers will be enabled to form an estimate for them- 

 selves, from the analysis and extracts which we have now laid before 

 them. 



XXXVIII. Proceedings of Learned Societies, 



LTNN^AN SOCIETY. 



1835. T> EAD a paper, by Thomas Taylor, M.D.,F.L.S., entitled 

 Jan. 20. — -IV '^ De Marchantieis.'' The author regards these plants 

 as constituting from their higher development a distinct group from the 

 HepaticfE, with which they have been hitherto associated. The paper 

 contains a description of twelve species, distributed into the following 

 genera, namely, 



1. Marchantia, Linn., of which M. polymorpha is the type. 



2. Fegatella, Caesalp. Raddi. Type of the genus M. conica, Linn. 



3. LunuUiria, Micheli. Type of the genus M. crMcia^a, Linn. 



4. Hygrophila. Type of tlie genus Marchantia irrigua, Wilson 

 in Hooker's Brit. F!. ; a new species discovered by the author and Mr. 

 William Wilson in various parts of Ireland. 



