I have no doubt, however, that we shall be able to obtain the characteristic reaction." As he spoke, he threw into the vessel a few white crystals, and then added some drops of a transparent fluid.

In an instant the contents assumed a dull mahogany colour, and a brownish dust was precipitated to the bottom of the glass jar.
"Ha! ha!" he cried, clapping his hands, and looking as delighted as a child with a new toy.

"What do you think of that ?" "It seems to be a very delicate test," I remarked.
"Beautiful! beautiful! The old Guiacum test was very clumsy and uncertain.

So is the microscopic examination for blood corpuscles.

The latter is valueless if the stains are a few hours old.