ETHAL. 147 



Now 33 atoms carbon, = 24*75 giving per cent 82-84 



33 atoms hydrogen, 4*125 ... 13*81 



1 atom oxygen, = 1*00 -. 3*35 



29-875 100-00 



This accords sufficiently with the mean of the preceding ana- 

 lyses to render it probable that margaron is formed by abstract- 

 ing an atom of carbonic acid and an atom of water from hydrous 

 margaric acid ; and if this be so, then the constitution of marga- 

 ron is C 33 H 33 O = 29-875. 



SECTION IL OF ETHAL. 



This oily-looking substance was discovered by Chevreui in 

 1818. He obtained it from the solid part of purified spermaceti, 

 to which he gave the name of cetin. It was saponified and the 

 soap decomposed by tartaric or phosphoric acid. The fatty mat- 

 ter which separates is a mixture of ethal with margaric and oleic 

 acids. These acids are combined with barytes and the excess of 

 barytes removed by boiling water. The whole is now digested 

 in cold but very strong alcohol, which dissolves the ethal toge- 

 ther with some margarate and oleate of barytes. When the al- 

 cohol is distilled off and the residue treated with absolute alcohol 

 or ether, the ethal only is dissolved, and may be obtained pure 

 by distilling off the solvent. 



The properties of ethal, as determined by Chevreui, have been 

 already detailed in the Chemistry of Inorganic Bodies, (Vol. ii. 

 p. 332.) 



In the Chemistry of Vegetable Bodies, (p. 321,) the subse- 

 quent analysis of ethal by Dumas and Peligot has been given. 

 They obtained, 



Carbon, . 79.2 



Hydrogen, . 14-2 



Oxygen, . 6*6 



100*0 

 They consider its constitution to be, 



16 atoms carbon, 12 or per cent. 79*34 



17 atoms hydrogen, = 2*125 ... 14*05 

 1 atom oxygen, =1 ... 6*61 



15*125 100*00 



