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Proceedings of the Royal Society 
b} r no means certain that it possesses that nature, Some years ago, 
Dittmar and Dewar* investigated the matter, and came to the con- 
clusion that meconic acid is dibasic though triatomic ; but their 
experiments are not supposed to completely elucidate the subject. 
All published statements regarding this acid are consistent with it 
being only dibasic, if we except one or two analyses of its metallic 
salts. Only two ethyl ethers are known, while hydromeconic acid, 
which is formed from meconic acid by the action of sodium- 
amalgam, forms dibasic salts alone. With morphia and with 
aniline tribasic compounds are not known, though the dibasic salts 
are easily prepared. 
There can be no doubt that the chief reasons for assuming the 
tribasic nature of meconic acid, are the statements which have been 
made concerning the composition and properties of the silver and 
lead salts, notably of the former. The object of the present paper 
is to prove that the alleged facts regarding these compounds do not 
rest upon solid ground. 
The meconic acid used in the experiments hereafter described 
was carefully purified, being obtained in the form of well-defined 
prisms perfectly free from colour. No impurities for which it was 
tested were found to be present, and the acid neutralized the 
required proportion of standard alkali. 
I. Meconates of Lead. 
(1.) Prepared by adding solution of lead acetate in excess to 
aqueous solution of meconic acid. Even after long-continued 
washing the precipitate still yielded to the filtrate lead and meconic 
acid, showing that the salt is not insoluble, as is sometimes stated. 
After drying at 120° C. the meconate was ignited, and the residue 
ignited with ammonic nitrate to oxidize the metal. 
8*295 grs. gave 4*22 grs. PbO = 50*87 per cent. 
8*260 „ 4.20 „ =50*84 
(2.) This salt was prepared in the same way as the above, 
at least there was no difference noticed in the method of pro- 
cedure. 
47*50 grs. gave 26*70 grs. PbO = 56*21 per cent. 
* Proc. Roy. Sec. Edin. 1867. 
