76 Intelligence and Miscellaneous Articles. 



Instructor of Mineralogy, &c, on w Chloride of Aluminium and its 

 Analysis." This paper extends over nearly twelve octavo pages, and 

 is one of the most perfect specimens of the lengthy ever inflicted on 

 the chemical world • about 2000 figures and symbols are employed, 

 and the results are commonly carried out to eight decimal places. 

 The conclusions arrived at are, that the atomic weight of alu- 

 minum, according to the experiments detailed, is 087920118, or 

 1*31880177, accordingly as we consider alumina a proto- or sesqui- 

 oxide; and that the hvdrated chloride of aluminum is composed of 



Chlorine 1 atom = 2.V52 



Aluminum 1 atom = 6 40 



Water 10 atoms = 68-08 



100-00 



ON VEINS OF CRYSTALLIZED CARBONATE OF LIME IN FOSSIL 

 WOOD. BY EDWARD CHARLESWORTH, ESQ. 



To the Editors of the Philosophical Magazine and Journal of Science. 

 Gentlemen, 



In the examination of some English specimens of fossil wood, from 

 several different localities, my attention has been drawn to a circum- 

 stance which I do not remember to have seen noticed, although I 

 think it can hardly have escaped the observation of others j I allude 

 to regularly formed veins of crystallized carbonate of lime, which in- 

 tersect the wood in a transverse direction, completely separating it 

 into a number of unequal lengths, and that without producing the 

 slightest displacement or alteration in the position of those fibres 

 which are immediately in contact with the intersecting substance. 

 My observation was first directed to this fact in some of the petrified 

 wood so frequently picked up on the Norfolk coast, and to which a 

 comparatively recent date is generally assigned : I believe, however, 

 that the most frequent instances occur in the secondary formations. 



A short time since a dealer brought me from Maidstone a block of 

 greensand containing a beautiful piece of dicotyledonous wood, which 

 illustrates in a very interesting manner the circumstance in question. 

 The specimen is about eight inches long, and is intersected by five or 

 six bands of carbonate of lime, which pass entirely through it, and 

 are then attached to the walls of the surrounding cavity. These trans- 

 verse veins are again crossed by longitudinal ones, so that a number 

 of cells are formed, presenting an appearance similar to that which is 

 constantly seen in the nodules of limestone from the London and 

 Kimmeridge clays, generally known by the name of Septaria. 



The portions of wood thus inclosed do not appear to have suffered 

 any derangement of structure, the continuity of the fibres being simply 

 interrupted by the extraneous substance. 1 am certainly inclined to 

 think that this effect was produced during the progress of petrifaction, 

 and that it is not the result of previous or subsequent infiltration. 

 As any facts connected with that process are interesting, I am in- 

 duced to bring these few remarks before your notice, thinking that they 



