131 
of Edinburgh, Session 1866 - 67 . 
But the effect of hydriodic acid on this group is totally different 
from its action on the fatty series. If comenic acid and concen- 
trated hydriodic acid are heated to upwards of 200° C., large quan- 
tities of free iodine separate out, mixed with a considerable quantity 
of free carbon. Hydriodic acid, therefore, is inapplicable as a re- 
ducing agent on these compounds. 
Seeing that no definite compound could be obtained by the 
agency of hydriodic acid, the action of pentachloride of phosphorus 
did not look very promising. Under the influence of this reagent, 
however, the acid sustained a perfectly regular decomposition, and 
did not break up in the way one would have anticipated from its 
general instability in presence of powerful reagents. If meconic 
acid is treated with three molecules of pentachloride of phosphorus, 
hydrochloric acid is slowly given off in the cold ; and if the retort 
containing the substance be heated to 100° C., the reaction takes 
place with great rapidity, torrents of hydrochloric acid are evolved, 
and oxychloride of phosphorus (PC1 3 0) distilled over. In order to 
separate the oxychloride of phosphorus, the whole was heated for 
some hours to 130° C. in a current of dry carbonic anhydride. Ter- 
chloride of meconyl remained as an intensely red, non-volatile, semi- 
solid substance, fuming in air, and decomposible by water, with the 
formation of an intensely dark-brown liquid. Several organic 
analyses of this substance were made, but as it was found impos- 
sible to free it from all traces of phosphorus, perfectly agreeing 
results could not be obtained. 
Found. 
The formula 
C 7 H0 4 Cl 3 requires 
Carbon, 
31-5 
32-9 
Hydrogen, 
07 
0-4 
Chlorine, 
44-5 
41-6 
As analysis did not give a satisfactory proof of the carbon group 
remaining entire in this reaction, a direct experiment was made 
with the view of estimating the amount of carbonic anhydride 
evolved. For this purpose a special apparatus was devised, by 
means of which the amount of any permanent gas produced during 
the reaction could be estimated. To effect this, the retort contain- 
ing the substance was connected with a tubulated receiver, to con- 
dense the oxychloride of phosphorus, and this joined to a small 
gasometer containing a saturated solution of chloride of sodium. 
