* 
Chemistry and Physics. 257 
CH: ’ . 
acid of the constitution { €HCl would be formed. This acid 
€0-0H 
corresponds to the ordinary lactic acid eH-OH. Wichelhaus 
has, however, ee that glyceric acid jreated with Lom om 
rie chlorid does not oem this chlorpropionic acid, but o: 
isomeric with it. Of course (assuming the equality of the fue 
carbon units of nésenetion); this can only be a chlorpropionic 
,-OH : 
acid corresponding to sarco-lactic acid, €H, whose constitu- 
- . €0-0H 
€H,Cl 
tion is{ €H, _. Hence the formula of glycerie acid must be 
9-0H 
€H,-0H €H,-0H 
| €H-OH and that of glycerin €H-OH . The action of phos- 
€0-6H 
P oric chlorid, then, substitutes chlorine for a hydryl-atom, belong- 
Ing, not to an aci id, but to-an alcohol residue; producing a body 
different from the br romine-compound obtained ‘by the direct action 
of bromine upon propionic acid. In this body, as Buff has shown, 
the bromine is attached to the middle carbon atom, giving the 
€H,: 
forinula ) CH Br , which may be compared with that of the chlor- 
propionic acid of Wichelhaus, given above. 
To which of these forms do the chlorhydrins et ? Is the 
elite in monochlorhydrin attached to the middle or to one of the 
end carbon-atoms? This question er has answered by reducing 
monochlorhydrin by means of sodium-amalgam. arn a a 
less liquid was obtained, boiling between 185° and 1 
ponding ewe to propylenic . os se is body Dy sn simple 
oxydation yields the ordinary la 
molecular constitution. In ‘order “3 decide hie point, the conver 
sion into lactie acid was effected by means of platinum-black ; 
the lactic acid thus formed was converted into the zine salt, oie its 
character established. It is hence certain that in the action of 
chlorhydrie acid upon glycerin, the chlorine replaces a hydryl-atom 
bel longin ging to an external carbon-atom, thus: 
Glycerin. Monochlorhydrin. cr glycol. Lactic acid. 
€H,-0H €H,Cl Le 
€H-9H €H-OH €H_OH €H_0H 
€H,-0H €H,-0H oH, -9H €0-0H 
In dichlorhydrin, a similar reduction would produce, accordin 
as the second atom of chlorine is united to the midale or to the 
outer carbon atom, propylic or  mopeogielie alcohol, thus :— 
Am. Jour. Sct.—Srconp Szrms, Vou. XLV, No. 134—Marcu, 1868. 
17 
