A new test for chloral hydrate has been devised by Frank Ogston,
namely, yellow sulphide of ammonium. On adding this reagent to a
solution of chloral of moderate strength there is at first no change
noticed, but in a short time the colorless solution acquires an orange
yellow color, and on longer standing turns brown and evolves a gas
of very disagreeable odor. Ogston's experiments show that a solution
containing ten milligrammes turns brown in six hours, and gives the
peculiar odor. With one milligramme the orange-yellow color appears
in twelve hours, but no odor. Croton chloral gives the same reactions,
but chloroform, chloric ether, and formic acid do not.
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