292 Domestic Science 



pipe into the form of a flat spiral, with the open end 

 projecting at right angles as indicated 

 in the figure. Fit a length of glass 

 tubing of somewhat smaller bore than 

 the metal piping to the open end by 

 means of a small cork or a short piece 

 of stout rubber tubing. Cool this piece 

 of apparatus by immersion in a vessel 

 containing melting ice. After it has 

 been in the ice for about five minutes, 

 remove the glass tube and fill the metal 

 tubing with ice-cold water. Repla-ce the 

 glass tube, and by pushing it into the 

 metal tube, cause the water to rise 

 some three or four inches in the glass lg " 



tube. Leave the leaden tube immersed in the ice 

 for another five minutes, and, at the end of that interval, 

 mark the level of the liquid in the glass tube. Assist 

 the melting of the ice by surrounding the vessel con- 

 taining it with a water-bath. The water in the bath 

 should be gently heated and its temperature should 

 not exceed 30 C. Place a thermometer in the vessel 

 containing the melting ice, and stir from time to time. 

 Should the water in the glass tube fall below the marked 

 position, note the lowest point reached and mark this 

 as before. When all the ice has melted, the tempera- 

 ture of the water formed will gradually rise. At this 

 stage remove the source of heat. As the temperature 

 of the ice- water slowly rises, the water in the glass 

 tube will be seen to sink. This indicates that this water, 

 while its temperature is being raised, is contracting, 

 thus behaving in the reverse manner to that previously 

 observed as common to other substances. The decrease 

 in volume will continue until a temperature of about 



