500 M. Lourengo on Polyglyceric Alcohols. 
Besides this there was formed at the same time another body 
of analogous properties, but possessing a greater viscosity. It 
boils at 275° to 285° under the pressure of 10 millims. ; it has 
the composition €9 H®°@7, and is derived from three molecules 
of glycerine with elimination of two molecules of water. It is 
analogous to triethylenic alcohol in the series of condensed 
glycols. 
In the crude product from which these bodies were obtained, 
there were several chlorine compounds which distilled at the 
ordinary atmospheric pressure, and were separated by fractional 
distillation. A portion of this, boiling between 230° and 270°, 
which chiefly consisted of hydrochlorate and dihydrochlorate of 
pyroglycerine, was treated with potash, by which chloride of 
potassium was formed, and a body obtained which, on purifica- 
tion and analysis, was found to have the composition 
C3 H° 
(6 F1294— C3 Hs} 
H2 
It is metameric with glycide, the existence of which has been 
placed out of doubt by Reboul’s researches*. Lourenco names 
it pyroglycide ; it stands in the same relation to pyroglycerine 
that glycide does to glycerine, being formed from it by the eli- 
mination of water. 
€° H® ¢? H° 
13 pO" —H?O= : how 
Glycide. 
2(€3 He 2(C8 HP; 
(E Ht }O°—H?O= (G He + 
Pyroglycide. 
There is another way of obtaining these polyglyceric alcohols, 
which throws some light on their formation. When glycerine 
was heated, and the part collected which distilled between 130° 
and 266°, and this portion treated with ether, an insoluble residue 
was left. This body gave distillates up to 300°, under a pres- 
sure of 10 millims., consisting of pyroglyceric alcohols. It is 
highly probable that in this decomposition, glycerine losing 
one molecule of water forms glycide, and this combining with 
one, two, or three equivalents of glycerine, forms polyglyceric 
compounds ; just as oxide of ethylene, in acting upon one, two, 
or three equivalents of glycol, forms polyethylenic alcohols. 
Lourenco points out that the formation of these polyethylenic 
alcohols suggests a plausible explanation of the formation of the 
different modifications of metaphosphorie acid, which are ob- 
* Phil, Mag. April 1861. 
