yi. Beilstein on Acetal. 289 



not the researches of Wurtz rendered it jjrobable that the ethers 

 of the glycols contain the same number of equivalents of cai'bon 

 as the glycols themseh^es. 



When iodide of methylene is treated with chlorine, iodine is 

 separated, and chloride of methylene, C- H^ CP, formed. It is 

 an oily liquid, which distils at 40° to 41° C, with an odour 

 resembling chloroform. The corresponding bromide, C^ H^ Br^, 

 is similarly formed. Butlerow's attempts to isolate the gas me- 

 thylene were unsuccessful. 



Wurtz and Frapolli* succeeded in transforming aldehyde into 

 acetal by acting on sodium-alcohol with the compound C^H^O^Cl, 

 which is formed by the action of hydrochloric acid on aldehyde. 



Beilstein t has performed the reverse of this operation by trans- 

 forming acetal into aldehyde. 



When acetal and glacial acetic acid are heated in a sealed tube 

 for two or three days to a temperature of 1.50° to 200° C, a 

 liquid is obtained which begins to boil below 50°. If the 

 vapours disengaged are received in ether saturated with ammo- 

 niacal gas, the characteristic ciystals of aldehyde-ammonia ai"e 

 obtained. The residual liquid contains acetic ether. The reac- 

 tion is expressed by the equation 

 C 12 H 1" 0* -h 2 (C-* H'i 04) = 2 (C* H3 (C* H^) 0*) -F C* H^ 0^ -+- 2 HO. 



Acetal. Acetic acid. Acetic ether. Aldehyde. 



Anhydrous acetic acid exerts a similar action. A liquid is 

 obtained from which aldehyde and acetic ether may be extracted, 



C12 Hi'*0'' + C8 H«06=2(C'* IP(C4 H^jO^) + 0* H^O^. 

 Acetal. Anhydrous Acetic ether. Aldehyde, 



acetic acid. 



From these experiments, acetal might be regarded as a combi- 

 nation of aldehyde with ordinary ether, 



C'2 HI-* 0^=04 H-* 02 + C8 Hio 02. 

 Acetal. Aldehyde. Ether. 



The same chemist J tried the action of pentachloride of phos- 

 phorus on acetal. He found that the action was different accord- 

 ing to the proportions taken. By the action of 2 equivs. of 

 pentachloride he hoped to obtain chloride of ethylidene, accord- 

 ing to the equation 

 C'2H'404 + 2PCP=2(C4H^Cl)-t-C''H«Cl-f 2P02CF-hHCl. 



Acetal. Pentachloride Chloride Chloride of Oxychloride 

 of phosjjhorus. of ethyle. ethylideue. of phos|jhorus. 



But the action appears to take place in a somewhat different 



* Phil Mag. vol. .wii. p. 27<>. 



+ Bulletin de la Socie'le Chimique de Paris, p. 18. J Ibid. p. 46. 



Phil. Mac/. S. 4. Vol. 18. No. 120. Oct. 1859. U 



