II. Researches upon the specific volumes of liquids

Abstract

The molecular weight of bromine is, as is well known, nearly equal tc the arithmetic mean of the molecular weights of chlorine and iodine hence the molecular weights of bromine and of iodine monochloride (I Cl are nearly identical. These substances closely resemble each other ii physical properties. Both are dark-red liquids about three times heavie: than water. Bromine boils at about 59°-5, and solidifies at —240,5 iodine monochloride melts at +24°·5, and boils at 101°: the intern between the boiling- and melting-points of the two compounds is approximately equal. It appeared to me of interest to determine (1) if the specific volume of these liquids exhibit a relation similar to that which is shown by their molecular weights, and (2) if the relation in their specific volumes i preserved in analogous combinations of the two bodies. I have accordingly determined the specific gravities, boiling-points, and rates of expansion of bromine and iodine monochloride, and of the compound which these substances form by their union with ethene, C 2 H 4 . Th observations will also serve to determine if bromine and iodine mono chloride preserve, when in combination, the volumes which they posses in the free state.