On the Growth of White Thorn. iy 



white ores of iron*; and, notwithstanding the author has 

 described at such length the properties of manganese, we 

 may say with M. Fourcroyfj " that one would be led to 

 believe, on reading it with attention, that it was written by 

 its author rather to furnish him with an opportunity of 

 speaking of this last metal under the name of white ore of 

 iron, than to detail the properties of carbonate of iron." 



By even supposing that lime J and manganese § enter 

 into the composition of spathic iron in any notable quantity, 

 we ought to conclude, from all the facts above stated, that 

 the denomination of carbonated ferriferous lime with man- 

 ganese, cannot apply to all the white ores of iron. But if 

 the identity in the form of carbonated lime, with the .speci- 

 mens which are the subject of this memoir, is well esta- 

 blished, how can we conclude that mineralogical character- 

 istics, drawn from external form, are sufficient for deter- . 

 mining the species? 



■■ ' ' ■ '■■,-,■ == 



VI. Experiments on the Growth of White Thorn, pointing 

 out a letter Method of propagating that valuable Plant 

 than had before been practised. By Samuel Taylor, 

 Esq. of Moston, near Manchester §. 



JL* or these experiments the silver medal of the Society for 

 the Encouragement of Arts, 8cc. was voted to Mr. Taylor, 



* It is remarkable enough that it was precisely in this dissertation that 

 Bergman substituted the expression of magnesium to designate manganese for 

 that of magnesia, to which the epithet of nigra is added, in order that the metal 

 might not be confounded with the substance known by the name of magnesia 

 alba. 



" Ne — vel cum magnesia alba confundatur, terminationem neutralem, no- 

 minibus metallorum omnium, excepta platina communem addidimus." 



f Systeme de Connoissances Chimiques. 



\ It is not astonishing fhat several chemists have found lime, since the ma- 

 trix of certain ores of spathic iron visibly contains a very great quantity of it. 



Bergman says, in speaking of this earth, — " Pondus calcis multum variat ; 

 in quibusdam paucas centesinias rcperimus. In spathosis circiter decima pars 

 ea constat, in alii, dimidjum, nunquam verp penitus defuit." 



§ As to manganese, it is so much the more interesting to ascertain if these 

 ores contain any of it, because the generality of metallurgists attribute to this 

 metal the property of producing natural steel. 



[| From Transactions of the Sadtly of Aits, &c. 1805. 



C 4 fron\ 



