32 
cuprous chloride crystals with a little of the dark-coloured 
powder) well washed with water. By levigation it was 
easy to separate the powder from the crystals and to submit 
it to a further examination. In order to free it completely 
from cuprous chloride it was heated in a beaker with a 
solution of ammonium sulphate in water, which dissolved 
out all the cuprous chloride and left the powder intact ; 
and the latter, on being dissolved in nitric acid, did not 
give any reaction for chlorine, whilst the presence of 
copper was very evident : hence there is scarcely any doubt 
about this substance being cupric oxide. The liquid portion 
contained free hydrochloric acid and cupric chloride. 
When the red deposit first commenced to form upon the 
sides of the tube a small quantity of violet-red crystalline 
cuprite was undoubtedly also present, but disappeared on 
the experiment being continued. I dissolved the red deposit 
in nitric acid and detected the presence of a large quantity 
of chlorine in the solution, also that of copper. Therefore I 
conclude that this red substance is the so-called cuprous 
oxychloride described by Wohler (Ann. Chem. Pharm. 
CXXX. 376). On exposing the substance to the air it takes 
up oxygen, and acquires a beautiful apple-green colour, 
becoming a cupric oxychloride which has probably the 
same composition as Atacamite. 
Chcdcotvichite . — Being desirous of ascertaining what the 
action of a moderately strong solution of sodium chloride in 
water would be upon pure artificially-prepared cuprous 
oxide when heated with it in a sealed tube, I employed the 
following method, viz. : The tube was heated in an air-bath 
for five days at a temperature varying from 150° — 180°, 
when small traces of a green substance (probably atacamite) 
were observed, the cuprous oxide had become dark-brown 
in colour, and on the sides of the tube there were small 
beautiful radiating tufts of an orange-red coloured substance 
closely resembling the prismatic variety of cuprite called 
