304 Intelligence and Miscellaneous Articles. 



ON THE DETECTION OF THE TRACES OF WRITING FRAUDU- 

 LENTLY ERASED. 



Professor Gazzari of Florence, having been frequently appointed 

 by the Tribunals to give professional evidence on trials of this nature, 

 instituted experiments on the subject, which, by showing him the 

 possibility of removing not only the ink, but also the materials em- 

 ployed in its removal, proved that cases might arise when the fraud 

 could not be detected in any other manner than by examining the 

 condition of the paper or other material written on. For this pur- 

 pose optical means were tried in vain, and immersion in water did not 

 show such a difference in the absorptive power of the written and 

 unwritten parts, as happens in the employment of certain sympathe- 

 tic inks; but on exposure of the suspected paper to a moderate 

 fire, the paper, which in consequence of the corrosive effects of the 

 ink was in those parts altered in its nature, was unequally acted on 

 by the process of carbonization, and thus the number and length 

 of the lines, and often the whole of the erased portion, were distinctly 

 revealed. — First Report of the British Association Jbr\ the Advance- 

 ment of Science. 



ON THE COMBINATIONS OF CHLORINE. BY M. SOUBEIRAN. 



The author of this paper (Ann, de Chim. et de Phys, tom. xlviii. 

 p. 1 1 3 ) states the following as the compounds of chlorine and oxygen 

 at present admitted to exist : 



Protoxide of chlorine 2 vols, chlorine + 1vol. oxygen, 



Deutoxide of chlorine 1 vol, -)- 2 vols, 



Chloric acid 2 vols, + 5 vols. 



Oxichloric acid 2 vols, + 7 vols. 



And he adds that some chemists admit hypothetically another com- 

 pound, viz. 



Chlorous acid, consisting of 2 vols, chlorine + 3 vols, oxygen. 



This is supposed to exist in the compounds called chlorides of 

 oxides. Stadion supposed he found it in the gas formed when con- 

 centrated. Sulphuric acid acts upon fused chlorate of potash. 



From numerous experiments M. Soubeiran arrives at the follow- 

 ing conclusions : 



1st. That the gas called protoxide of chlorine is a mixture of 

 chlorine and deutoxide of chlorine ; 



2ndly. That the compounds known by the name of chlorides of 

 oxides are mixtures of a metallic chloride with a chlorite ; 



3rdly, That chlorous acid is undoubtedly formed of 2 volumes 

 of chlorine and 3 volumes of oxygen ; 



4thly. That mineral or organized bodies put in contact with 

 chlorites are oxidized by the oxygen of the chlorous acid, and some- 

 times by that of the base; 



5thly. That the bleaching by chlorites results from the oxidize- 

 ment of the elements of the colouring matter by the oxygen of the 

 chlorous acid ; 



6thly. That chlorine has a stronger bleaching or decolouring power 

 than the chlorites ; 



7thly. That the chloride of lime, in decomposing alcohol, gives 



rise 



