INDUSTRIAL PROGRESS DURING THE YEAR 1874. clxxxiii 



From the foregoing, the author draws the following con- 

 clusions: "It is not impossible that future discovery may- 

 succeed in explaining this anomaly, in harmonizing apparent 

 inconsistencies, in eliminating the sources of error, and in 

 reducing the operation to practical certainty; but in the 

 state of spectroscopic science as it now exists, so far as I 

 have been able to perceive, l^have arrived at the opinion, 

 not without regret, that assaying by means of the spectrum 

 analysis is impracticable for the purpose of Mint operations. 



In connection with the important subject of the artificial 

 preservation of timber, the process of M. Hatzfeld, lately de- 

 scribed in a paper before the French Academy, is worthy of 

 comment. The author in question proposes to inject into 

 the wood, by the Boucherie process (the hydrostatic pressure 

 of a heavy liquid column), or some similar plan, a solution 

 of the acid tannate of iron. The principle upon which the 

 merit of the plan is based is stated by the author to be that 

 the action of tannin upon vegetable tissues is analogous to 

 that which it exercises upon the animal tissues, effecting in 

 the former a kind of tanning, which will have for result the 

 formation of hard and imputrescible tannates, quite analo- 

 gous to the gelatinous tannates produced in the tanning of 

 skins. By this application, therefore, he proposes to fix the 

 putrescible matters in the wood, to the presence of which its 

 rotting is very properly attributed, in unalterable combina- 

 tions, thus preventing their decomposition. The French gov- 

 ernment and several of the French railroad companies are 

 testing the merits of the process. 



In the field of illumination and heating nothing of special 

 importance has transpired during the year to warrant men- 

 tion, save perhaps some successful experiments in London 

 with the electric light of MM. Ladyguin and Kosloff. The 

 features of this plan consist in having the carbons placed in 

 a closed glass vessel filled with a gas not containing oxvgen, 

 the sticks being held in place by metal connections of pe- 

 culiar construction. The lamps experimented upon were 

 nine in number; six having two carbon-rods each, and the 

 other three one each. The glowing of the carbons takes 

 place throughout their entire mass. The experiments dem- 

 onstrated satisfactorily the fact that the electric current 

 could be subdivided to operate a number of lights simulta- 



