Dry ice, sometimes referred to as  cardice  (chiefly British chemists), is the solid form of carbon dioxide. It is used primarily as a cooling agent.Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere).It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.t is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.
Maryland is also called the Old Line State and Free State.The Old Line nickname was given during the Revolutionary War, when 400 soldiers in the First Maryland Regiment fought a British force of 10,000 and helped General George Washington's army to escape.
For a closer examination of the background on this nickname, see: The Origin of the Old Line State , by Ryan Polk (2005). Free State. Maryland was first recognized as a Free State on November 1, 1864. On that date, the Maryland Constitution of 1864 took effect.