CHEMICAL SCIENCE. 201 



baden has lately published a minute analysis of a black variety 

 of cast-iron, which, besides a small amount of slag which was in 

 mechanical combination, showed the following composition in 100 

 parts : — 



Per cent. 



Metallic Iron 93.279 



Metallic Aluminium 0.028 



Metallic Manganese 0.388 



Metallic Chromium 0.027 



Metallic Vanadium 0.012 



Copper . 0.009 



Arsenium , . 0.015 



Antimony 0.011 



Cobalt and Nickel 0.035 



Zinc trace. 



Calcium 0.072 



Magnesium 0.010 



Titanium 0.024 



Phosphorus 0.459 



Sulphur 0.036 



Silicium 3.265 



Carbon (chem. comb.) 0.086 



Graphite 2.171 



MANUFACTURE OF WHITE-LEAD, 



A recent numlier of the '• Bulletin de la Society d'Encourage- 

 ment" contains the text of a report by M. Barreswil on M. Ozoiit"'s 

 process for the manufacture of white-lead. It resembles in the 

 main that proposed by 1'henard many years since, in which car- 

 bonic acid gas is passed through a solution of subacetate of lead. 

 The novelty consists in the manner of producing the carbonic 

 acid, which is as follows : The gases proceeding from coke burnt 

 in a specially-constructed furnace are, after having been washed, 

 led through a series of vessels containing a solution of carbonate 

 of soda, which thus becomes converted into bicarbonate. This 

 solution is pumped into a cylinder, where it is raised to a boiling 

 temperature. The eifect of this operation is to drive off half the 

 carbonic acid, which is then passed into a vessel containing a so- 

 lution of basic acetate of lead, as in the ordinary method. M. 

 Ozouf states that by proportioning the quantity of carbonic acid 

 gas to the composition of the subacetate operated upon, he is able 

 to produce at will white-lead of any definite composition, — a 

 point of some practical importance. A specimen furnished by 

 him showed on analysis a composition represented by the formula 

 3 (PbO, Co2) -\- Pbb, HO. Several ingenious contrivances for 

 l^reserving the health of the workmen engaged in M. Ozouf 's 

 manufactory at St. Denis are described in the report. 



NEW PROCESS OF MAKING SODA. 



Mr. A. G. Hunter of Rockcliffe Hall, near Flint, has achieved 

 a discovery, which seems likely to lead to a most valuable modifi- 

 cation iu the process of making soda. It has long been known 



