220 MR THOMAS HENRY ROWNEY ON A NEW SOURCE 
given off; and if the operation be performed in a retort with a receiver attached, 
this compound is found floating on the water that passes over during the opera- 
tion. It is also rendered soluble by being digested with a strong solution of 
caustic potassa for two or three days on the sand-bath. On adding HCl or 
HO, SO, to the cold alkaline solution, a dark oily mass rises to the surface; this 
was filtered and washed with cold water. I found that the best way to obtain 
the acid pure, was to dissolve it in a dilute solution of NH,O, and then to add 
Ba, Cl until it ceased to give a precipitate; this precipitate was filtered and washed 
with cold water, then dissolved by boiling with water, filtering whilst hot, and 
allowing the filtrate to crystallize. It is sometimes dissolved with difficulty by 
boiling water, owing to its forming hard soapy masses during the boiling ; by crys- 
tallizing the baryta salt two or three times, it becomes nearly colourless. It was 
then decomposed by boiling with NaO,CO,, and filtered from the precipitated 
BaO, CO,, dilute HO, SO, was added to the filtrate to separate the capric acid, 
and by these means it was obtained nearly colourless, and in a solid state. To 
obtain it perfectly pure, it was dissolved in alcohol, and a large quantity of water 
was added to the alcoholic solution, the mixture becomes turbid, and after stand- 
ing for some hours capric acid crystallizes out; and by repeating this process it 
may be obtained perfectly pure and colourless. The mother liquors from the 
baryta salt were concentrated by evaporation and then boiled with NaO, CO,, 
filtered from the BaO, CO,, and the filtrate decomposed by HO, SO,; the capric 
acid obtained from this portion was mixed with a small quantity of an oily acid, 
the quantity was so small that I was not able to ascertain its constitution. 
Capric Acid. 
Capric acid, as obtained in the manner I have described, is a solid, white, and 
crystalline compound, having a faint odour, and fuses readily when taken be- 
tween the fingers. It is very soluble in cold ether and alcohol, and does not crys- 
tallize from these solutions. It is insoluble in cold water, but dissolves sparingly 
in boiling water, and crystallizes from this solution on cooling in the form of 
scales. It is also soluble without decomposition when boiled with concentrated 
nitric acid, and is precipitated from this solution by the addition of water. It is 
obtained in a mass of needle-shaped crystals by the addition of water to the alco- 
holic solution. Its specific gravity is less than that of water. The crystallized 
acid commences to fuse at 81° Fahr., and the mercury of the thermometer conti- 
nues to rise to about 116° Fahr. before the whole is completely fused. When 
allowed to cool, it becomes solid at 81° Fahr. The fused acid is slightly coloured, 
and has a faint smell; it becomes crystalline on cooling. This fusing point 
differs from that generally given. Gdrcxy gives it at 86° Fahr., and others have 
stated it to be from 60° to 66° Fahr. These differences probably arise from im- 
pure acids having been used. For analysis the crystallized acid dried im vacuo 
over sulphuric acid was employed. 
a 
‘ 
} 

