1835.] Scientific Intelligcitce. 315 



2. The occurrence of napthaline in a coal gas work is not new^ as 

 it was first obtained from that source. 



3. The suggestion of my correspondent in reference to the iden- 

 tity of bicalcareo carbonate of barytes, and the new form of baryto- 

 calcite described by Mr. Johnston, I consider to be quite correct. A 

 similar remark was made to me immediately after the publication of 

 the paper in the " Records." I am glad to have an opportunity of 

 noticing the circumstance, because I observe that Mr. Johnston's 

 paper, in which he draws inferences in support of a peculiar theory, 

 has been translated into the German journals. An opportunity is 

 thus suggested to him of repeating his analysis, and corroborating 

 his first result, or correcting his error. 



I may take this opportunity of remarking upon the observations of 

 another correspondent who has been so good as to favour me with 

 some useful hints, that the object in employing italics to represent 

 the oxides of iron in the cases referred to, was merely to draw a dis- 

 tinction between that base when united with acids and when united 

 with sulphur. Again, when only one compound of a base and 

 oxygen is found in the mineral kingdom, it seems unnecessary to 

 characterize it, as far as mineralogy is concerned, further than as being 

 in union with oxygen. , 



The propriety of adopting Berzelius's symbols, by which I under- 

 stand the points for oxygen, the commas for sulphur, &c. appears at 

 present problematical, as they open the way for a kind of practical 

 alchemy, are only used by his own pupils, and a few others, and will 

 be of no service except in inorganic chemistry. Is not SO^ for sul- 

 phuric acid, and Fe S for sulphuret of iron much more intelligible, 



and less liable to be mistaken by the printer or reader than S or Fe. 

 This plan of attaching a new signification to the instruments of 

 punctuation may lead, and has led to great abuses, while the mere 

 employment of initial letters and figures is not likely to do so. I 

 should be glad to hear the arguments of those who are interested in 

 the question, in reference to these two kind of symbols. It is only 

 by a public discussion that any chance of settling the point can be 

 anticipated. Let this be done concisely, and it will be readily dis- 

 covered upon which side the strength of argument lies; we shall then 

 be able to present our readers with a useful set of tables. 



III. — Blue Velvet Copper. 

 ( To the Editor of the Records of General Science. 



Sir, — Kupfersamniterz, the blue velvet copper, is quoted by Mr. 

 Allan (Manual, p. 84) as " principally from Moldawa on the Ban- 

 nat." " From its extreme rarity, the characters of the species have 

 not yet been accurately ascertained." When this shall have been 

 done, it will probably be found not entitled to rank as a distinct spe- 

 cies. It is occasionally raised in Cornwall, and one or more Cornish 

 specimens is placed in every respectable collection in that county, 

 amongst the arseniates of copper, though it may not, perhaps, have 

 been correctly analyzed. But in the Scorrier collection is a good suite of 

 this species, appearing to connect it with Strahlertz, the oblique pris- 

 matic arseniate. The suite runs from a fine smalt-blue velvety tu- 



