]52 ON MURIATE OF TIN, 



45 of oxigen to 100 of the metal. It is true Mr. Bucholz 



Bucholz. could not combine more than 42 parts of oxigen with 100 



of iron, as we did in our first experiment: but mine-engineer 



Gueniywiu. Gueniveau combined 44 parts of oxigen with 100 of iron in 



an experiment similar to that of Bucholz, as he informed me 



in a letter I received from him. However, as it is extremely 



difficult to have pure iron, exempt both from carbon and 



oxigen, wc should consider the highest result as nearest the 



truth. 



Darso'sexperi- This difference in the quantity of oxigen combined with 



jnents appa- • j n tne experiments of Mr. Darso and ours leads us to 



rently errone- r , . . 



ous. believe, that some substances mixed with his products, ot 



which he did not take account. Our results bring back 

 the question to the point at which it was before the experi- 

 ments of Mr. Darso. If the precipitate obtained by The- 

 Th« white ox. n*:rd be really a white oxide with less oxigen than the 

 ide still re- green, there must be three oxides of iron, the white, green, 

 mains to be ex- , . , • i r • ..• r. ,, ■ 



arauied. and red: to tl^e nature and degree of oxigenation ot this 



precipitate therefore our inquiries should be directed, to 

 determine whether, as Proust asserts, there be but two de- 

 grees of oxigenation ; one at a maximum with 45 of oxi- 

 gen, and the other at a minimum with 30. 



XIII, 



On the muriate of Tin; by Mr. E. Berard, Exprofessor 

 of Chemistry at the Medical School at MontpeUier, of the 

 Academy of Garth, Sfc.* 



reparation of JL HE. preparation of muriate of tin in a large way has fur- 

 munate of tin n j sne d. me with opportunities of observing some facts, 

 which I think it may be of use to record. They will form 

 a supplement to those, hat have been described by various 

 men of learning, and may serve to hasten the period, at 

 which the art of dyeing will r ceive from chemistry a cer- 

 tain and uniform method of preening and employing 

 the composition for scarlet, which is a species of salt of tin. 



* Annales de Chimie, vol. LXVI1I. p. 78. 



' The 



