116 



By acting on mtro-terephthalic acid with reducing agents, it 

 undergoes the same change as other nitre-compounds. The product 

 of this reaction is the oxy-terephthalamic acid, or the analogue of the 

 glycocoll of the formula C 8 H 7 NO 1 . This new member of the glyco- 

 colls is a lemon-yellow substance, crystallizing in thin prismatic, and 

 sometimes moss-like forms. It is very slightly soluble in cold 

 water, alcohol, ether, and chloroform. Like other substances of this 

 kind, terephthal-glycocoll combines \vith bases as well as with acids. 

 The salts formed with the bases are crystalline ; they are readily 

 soluble in water and dilute alcohol, yielding colourless solutions of 

 most remarkable fluorescent properties, which have been investigated 

 by Professor Stokes. 



The aqueous and alcoholic solution of the pure terephthalic glycocoll 

 shows the same properties. The compounds with acids crystallize 

 well, and if dissolved in a large quantity of water decompose. They 

 do not possess the fluorescence when in their acid solution. 



The ether-like compounds of oxy-terephthalamic acid are obtained 

 by acting upon the corresponding ethers of the nitro-terephthalic 

 acid with reducing agents. The methylic ether is a beautiful cry- 

 stalline substance, readily soluble in warm alcohol, but much less 

 soluble in any of the solvents than nitro-terephthalate of methyl. 

 The ethylic ether crystallizes in large crystals with an appearance 

 resembling those of nitrate of uranium. The solutions of this ether 

 possess the fluorescent property in the highest degree. Oxy-tere- 

 phthalamate of methyl and ethyl combine with acids and form well- 

 defined salts. Oxy-terephthalamic acid, as well as its ether, are 

 readily acted upon by nitrous acid, this reaction giving rise to a 

 number of new derivatives, which vary in their nature according to 

 the condition in which the reaction takes place. 



M. Griess has lately made us acquainted with a new class of 

 remarkable substances which are obtained by the action of nitrous 

 acid on a certain class of nitrogenous bodies. The several derivatives 

 he obtained by this reaction from oxy-benzamic acid have their repre- 

 sentatives in the bibasic terephthalyl series, and are obtained with the 

 utmost facility. On acting with nitrous acid upon an aqueous solution 

 of the oxy-terephthalamic acid instead of an alcoholic solution, as is 

 employed in Griess' s reaction, this substance is readily decomposed, 

 nitrogen is given off in large quantities, and there gradually separates 



