174 On the Dcjmilt Proportions m which ike [March, 



Article III. 



Experiments to determine the Definite Proportlovs m which the 

 Eleinents of Organic Nature are comhined. By Jacob Berzclius, 

 M.D. F. R.S. Professor of Chemistry at Stockholm. 



III. Analysis of the Ternary Oxides. 



{Continued from p, 101.) 



5. Acetic Acid. — Among my experiments on the water of com- 

 bination of the salts, I gave two analyses of acetates ; namely, 

 acetate of lime and acetate of soda, from which I concluded that 

 100 of acetic acid neutralize a quantity of base containing from 

 1571 to 15-89 of oxygen. 



I have thought it necessary to repeat these experiments with still 

 greater accuracy. I held acetate of lime for several hours in the 

 highest temperature to which it could be exposed without risking 

 decomposition : 10 parts of this salt burnt in a platinum crucible 

 to the state of pure quick-lime left 3*54 of residue. Hence acetate 

 of lime is composed of 



Acetic acid 64'6 100 



Lime 35-4 54-8 



100-0 



These 54-8 parts of lime contain 16-43 of oxygen, I took very 

 pure crj'stals of acetate of lead, reduced them to powder, and put 

 them into a vacuum with sulphuric acid, in which 1 left them for 48 

 hours. I chose this method because acetate of lead undergoes a 

 slight decomposition in the open air, attracting carbonic acid, and 

 letting go a little acetic acid ; and when heat is applied, a part of 

 the acetic acid flics off along with the water. In three different 

 experiments, the loss of weight was 14-29, 14-32, and 14-5 per 

 cent. These variations depend upon the impossibility of deter- 

 mining when all the humidity mechanically retained is dissipated, 

 and the salt begins to effloresce. The salt effloresced in this 

 manner, when heated in a retort, gave out neither water nor acetic 

 acid (I mean before it began to be decomposed) ; doubtless because 

 acetic, like many other acids, is unable to exist in a separate state 

 when entirely deprived of water or some other oxide with which it 

 may combine. 



A hundred parts of effloresced acetate, analyzed by combustion, 

 and by driving off the acetic acid by means of nitric acid, and 

 decomposing the nitrate by heat, produced in different experimci 

 from 06- b to Gi^-^j, of oxide of lead. Hence it is composed of 



its 



