Apparatus for producing reactions in colorimetric cells

In an apparatus for determining a property of a given sample, an outer container having an open top, an inner container also having an open top and being small enough to be received entirely within the outer container with both of said open tops directed upwardly and with the open top of said inner container being situated substantially below the open top of said outer container, a tubular colorimetric cell having opposed ends one of which is closed and the other of which is open, and tubular connecting means having opposed open ends and an unobstructed, completely open internal tubular passage extending from one to the other of said open ends and having an internal cross sectional area which is too small to receive said inner container, said tubular connecting means being removably connected with said open top of said outer container and said open end of said cell for fluid-tightly connecting said cell to said outer container with the interior of said cell communicating with the interiors of said containers so that when a sample and reagent are respectively situated in the interiors of said containers in an amount according to which the inner container when situated within the outer container will extend above the level of the contents of said outer container, said connecting means can fluid-tightly connect said cell to said outer container to enable both containers and said cell to be inverted as a unit for discharging the contents of both containers into said cell to mix therein and provide a reaction according to which a property of said sample may be measured in an instrument.