1823.] Scientific Intelligence. 309 



entitled, " On the Results of Computations relative to the 

 Parallax of « Lyrse from Observations made with the Greenwich 

 Mural Circle, compared with those of Dublin; by Dr. Brinkley, 

 Prof, of Astronomy, Trin. Col. Dublin :" this was a highly inte- 

 resting paper. 



Article XII. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Mr. Faraday's Liquefaction of the Gases. 



We have already described, at p. 304-, in our report of the proceed- 

 ings of the Royal Society, the means by which Mr. Faraday has suc- 

 ceeded in reducing chlorine to the liquid state ; and we are happy to 

 announce that he has also succeeded, by analogous modes of operation, 

 in liquefying the following aeriform substances : euchlorine, nitrous 

 oxide, sulphurous acid, sulphuretted hydrogen, carbonic acid, and 

 cyanogen. All the liquids thus produced are colourless, with the 

 exception of euchlorine; and all are perfectly fluid, and highly volatile. 



II. Rc-ojiening of Mr. Soiuerby's Museum. 



We feel much satisfaction in announcing that the late Mr. Sow- 

 erby's Museum of the Natural Productions of Great Britain, at No. 2, 

 Mead-place, Lambeth, is again opened for the inspection of his 

 friends and the lovers of natural history, every Tuesday from eleven till 

 four o'clock, under the direction of his sons and executors, James de 

 Carle Sowerby, FLS. and Charles Edward Sowerby. 



III. Prof. Daubeny on Rochs that contain Magnesia. 



Dr. Daubeny having withdrawn his paper on this subject from the 

 Royal Society, in the hope of its appearing at some future time, in a 

 more complete state, has requested us to correct two mistakes in our 

 report of it, published in the Annate for February, p. 150. 



We have there represented Dr. D. as saying, that the presence of 

 magnesia in the oolites " has not been ascertained with certainty;" 

 whereas, he states, there are several specimens of them in the cata- 

 logue at the end of his paper, which are mentioned as containing that 

 earth. In the second place, Dr. Daubeny observes, we have transfer- 

 red to his mode of separating lime from magnesia, the objections which 

 he had alleged against preceding methods, and from which he imagines 

 his own to be exempt; " for it will be seen by reference to my paper 

 in the Edinburgh Philosophical Journal," he continues, " that the 

 difficulty of driving off the ammoniacal salts and water originally pre- 

 sent, without at the same time decomposing the magnesian sulphate, 

 was my inducement for substituting that scheme of analysis which is 

 inserted in the Annate, the peculiarity of which consists in its enabling 

 the operator to calculate the quantity of magnesia by merely ascer- 

 taining the amount of the sulphate of lime obtained, deducing from 

 thence that of the lime, and comparing the result with the quantity 

 taken up originally by the acetic acid." 



