OF ARTS AND SCIENCES. 2G9 



Paraiodbenzaldehyde, C ( .II 4 ICOH. 



0.7339 gr. of substance gave on combustion 0.9665 gr. C0 2 . The 

 hydrogen was unfortunately lost. 



Calculated for C 7 n 5 IO. Found. 



Carbon 36.20 35.90 



White needles melting at 73°. With oxidizing agents it forms 

 paraiodbenzoic acid. 



Mdabrombenzaldeliyde, C c TI 4 BrCOH. 



0.5900 gr. of substance gave on combustion 0.9800 gr. C0 2 and 

 0.1320 gr. H,0. 



Calculated for C 7 H 5 BrO. Found. 



Carbon 45.40 45.30 



Hydrogen 2.70 2.49 



A colorless heavy oil, showing no signs of solidifying even in a 

 freezing mixture of ice and salt. With oxidizing agents, or on 

 exposure to the air, gives very easily metabrombenzoic acid. 



Orthobrombenzaldehyde, C fi II 4 BrCOH, was prepared from the liquid 

 orthobrombenzylbromide, as this work was done before it had been 

 obtained in the solid state. Instead of distilling the product of the 

 reaction, the plumbic bromide and water were decanted while hot, 

 leaving the aldehyde as a heavy oil, which was washed with water, 

 purified as before described with acid sodic sulphite, dried, and ana- 

 lyzed. 



0.5440 gr. of substance gave, on combustion, 0.8990 gr. C0 2 and 

 0.1476 gr. R,0. 



Calculated for C 7 H E BrO. Found. 



Carbon 45.40 45.08 



Hydrogen 2.70 3.01 



A heavy colorless oil, much more rapidly oxidized by the air than 

 any of the other substances described in this paper. 



The three para-compounds yielded, when treated in alcoholic solu- 

 tion with sulphuretted hydrogen, the thioaldehyde, as a reddish white 

 varnish, which it did not seem worth while to investigate. 



