133 
of Edinburgh, Session 1866-67. 
carbon, C 5 H 4 , below benzol. From our general knowledge of this 
class of compounds we would expect the formation, by the action of 
pentachloride of phosphorus, of a chloride of a hydrocarbon. We 
investigated this reaction on the small quantity of pyromeconic acid 
we had at our disposal. When pyromeconic acid, in presence of 
oxychloride of phosphorus, was heated in a sealed tube to 200° C. 
with an excess of pentachloride of phosphorus, and the result of 
the action treated with water, a brown oil separated out, which, 
when distilled, yielded a colourless oil that boiled above 200° C. 
This substance did not fume in the air, and remained in water with- 
out dissolving for days. The analysis gave somewhat anomalous 
results, the percentages of its constituents agreeing very exactly 
with the formula C ]0 H 5 Cl 9 O 3 . This highly chlorinated substance 
seems to approach nearly to the chloride of a hydrocarbon. 
Unfortunately, pyromeconic acid is a substance which cannot be 
easily investigated, as it is extremely difficult to procure in any 
quantity. In the course of our experiments we obtained only one 
per cent, of pyromeconic from meconic acid, so that until a better 
process for preparing this substance is discovered, it must remain 
an open question whether pyromeconic acid is a lower homologue 
of pyrogallic acid. 
3. On the Action of Ammonia on Bichloracetone. By X)r 
A. Crum Brown. 
This paper contains some further details of the properties and 
composition of the substance mentioned in a former note (. Proceed - 
ings , vi. 75). 
The substance is produced by the action of dry ammonia gas on 
dichloracetone. A low temperature favours its formation. It 
forms colourless needles, generally radiating from central points. 
It is extremely unstable, and can only be preserved in an atmo- 
sphere of dry ammonia. In vacuo over sulphuric acid, even at a 
temperature of 0° C., it decomposes into ammonia, dichloracetone, 
and a viscous substance, which has a smell recalling that of 
acetamide. The same decomposition takes place in dry air. 
Hydrochloric acid converts it into dichloracetone and chloride of 
ammonium. It may be fused in an atmosphere of dry ammonia, 
