TR.INSACTIOXS OF SECTION B. 671 



them not to be a uniform product, but by repeated recrystallisation from bot 

 benzene a substance -was obtained approximately answering to the formula 

 CjjHjoOloO. By protracted crystallisation we shortly expect to obtain a perfectly 

 pure product. The corresponding ^- and -y-derivatives have not yet been pre- 

 pared. 



a-dibrom-pyrocresol G^^^^v.P, obtained by adding Br to the acetic acid solu- 

 tion of pyrocresol, forms thick white elongated plates melting at 215°. 



y and ^ pyrocresol form very similar compounds, and the oxides also combine 

 with bromine. 



A chloride of a-p\jrocresol — probably OjjHuCl., — has been obtained by acting upon 

 a solution of pyrocresol in carbon tetrachloride with a solution of PCI5 in the same 

 solvent ; the chloride is gradually precipitated as a yellowish powder, which on 

 standing soon decomposes, forming a resinous, brown mass. The /3 and y isomerides 

 have not yet been prepared. "NVhen dry a-pyrocresol is mixed with PCI- and 

 heated ; a green mass is formed solujble in benzene or chloroform with a beautiful 

 green colour. Upon strongly heating in an oil bath the green colour disappears. 

 The final product, after being well washed with hot water to remove phosphorus 

 chlorides, is found to contain chlorine, but cannot be recrystallised, the solutions 

 invariably drying up to a hard, transparent resin. 



Salplto-derividivcs. 

 The pyrocresols can be sulphonated, two of the hydrogen atoms being replace- 

 able by SO3II. The Ba- and Na-sulphonates have been prepared. After oxidisino- 

 sulphonation no longer takes place, hence it would seem that the hydro"-en atoms 

 replaceable by SO„II are the same which are exchanged for oxygen upon oxidation. 



Meduction of the Pyrocresols. 

 The first attempts to effect a reduction of the pyrocresols failed on account of 

 the extreme stability of these bodies. Only recently we have succeeded in reduc- 

 ing a-pyrocresol, and by preliminary experiments have found that /3-and -y-pyro- 

 cresol can also be reduced, but so far we have only studied the n-derivative more 

 closely. On beating a-pyrocresol in sealed tubes with 80 parts of a solution of 

 HI in acetic acid or water and excess of amorphous phosphorus to 300°, a 

 copious separation of iodine took place, and an oily liquid was found floating on 

 top of the mixture. The contents of the tubes were neutralised, distilled with 

 superheated steam, and the oil obtained dried with KHO,and repeatedly distilled over 

 metallic potassium. The pure oil is colourless and non-fluorescent, it has a slight 

 smell reminding of paraffins, and does not solidify even in a freezing mixture, nor 

 do any of the difi'erent parts obtained from it by fractionation. Upon fractionatmg 

 the oil turned out to be a mixture ; the portion boiling about 276° was collected 

 and analysed, the analysis corresponding to the formula C',-,H^3-i 5 l^ut of course the 

 exact amount of hydrogen cannot be ascertained by analysis only. Three vapour 

 density determinations in an atmosphere of hydrogen and diphenvlamine bath by 

 V. Meyers method gave the following data : 



=1) 



Mean : 107-92 (calculated for C15H30 : 106). 



The oil cannot be nitrated by UNO,, or nitrating mixture ; upon heating with 

 HNO3 a kind of resin is formed lighter than water. Bromine and strong H,,SO^ 

 scarcely act upon it. The quantity of the oil obtained so far was insufficient for 

 further tests, and the lower boiling portion could not be examined more com- 

 pletely for the same reason. Experiments to prepare larger quantities are now 

 being made. 



