528 M. E. Breunlin on the Constitution of 



cei'iue at 100° C, so large a quantity of formic sether as to be 

 an excellent source of that substance. The greater part of the 

 oxalovinic acid which I employed in my experiments was pre- 

 pared by the action of pure hydrate of potassa upon oxalic a:thcr, 

 using equivalents of the two bodies ; yet on testing a mixture of 

 absolute alcohol and dry oxalic acid left in contact since June 

 1854, the presence of a considerable amount of the acid oxalate 

 of sethyle was indicated ; and the fluid part of this mixture, treated 

 with an equal volume of glycerine, yielded on distillation about 

 one-fourth its weight of formic aether. 



The formiate of fethylc produced in the manner above described 

 agreed in odour, boiling-point, and specific gravity, with the 

 formic a;thcr obtained by the ordinary methods ; but in order to 

 satisfy myself of its identity, I bm-nt a portion of the body with 

 oxide of copper in the usual manner ; the following are the de- 

 tails of the analysis : — 



0-2015 grm. of substance gave 0-36 grm. carbonic acid, and 

 0' 14525 grm. water. 



The theoretical and experimental per-centages of carbon and 

 hydi'ogen in formic aether are as follows : — 



Tlieory. Experiment. 



Carbon . . . 48-68 48-7 



Hydrogen . . 8-1 8-0 



From the results of some qualitative experiments, I think I 

 am justified in concluding that formiate of methyle may be pro- 

 duced from oxalo-methylic acid by the action of glycerine ; and 

 that it would not be without interest to examine the behaviour 

 with glycerine of the other members of that series of bibasic 

 acids to which oxalic acid belongs, not indeed only the acids, but 

 the acid rethyle and methyle compounds. 



LXVIII. On the Constitution of Green and Blue Ulti-amarine. 

 By E. Breunlin of JVeissenau*. 

 \NYj of the most beautiful and important mineral colours is 

 tliat called ultramarine. Although we have long known 

 it, and it is now produced in large quantities and is extensively 

 applied, its true constitution has never been clearly ascertained. 

 The theories hitherto ])roposed have been grounded on the mode 

 of its preparation, and on a few analyses, but none of them has 

 obtained authority; they are not precise, and prove little by 

 means of numbers; perhaps also the materials used for the 

 analysis were faulty. 



* Tianslated by Dr. E. Atkinson from the Annalen der Chemie und 

 Pharmccie for Mai-ch l!?5(j. 



