160 ON LATERAL rRESSUEE. 



more than a quarter of a pint of water. The gas 

 is then to be lighted, and the heat brought up 

 gradually by means of both the gas coils ; when 

 the heat is up to the desired temperature, then the 

 small coil will be found sufficient to keep it at that 

 degree of heat. 



The lid of the vulcanizing chamber must be 

 always steam-tight when in use — this will prevent 

 the escape of any smell. This is easily done by 

 dusting some French chalk on that part upon 

 which the lid is screwed down each time of vul- 

 canizing. 



When the time necessary for hardening is com- 

 pleted, the apparatus must be allowed to cool 

 down before opening the lid. 



Mr. Bridgman read the following paper on "Lateral Pressure:^' — 



'' Lateral pressure^ ^ is a term usually applied to 

 certain results arising from an abnormal state of 

 the human denture. 



It is by no means restricted in its application, 

 but is commonly assigned as a cause for any par- 

 ticular effect, either of crowding, or decay in the 

 teeth, or any other deviation from the normal 

 condition. But, although it is thus the assertion 

 of a fact of common occurrence, it does not appear 

 to have been made the subject of especial atten- 

 tion ; nor, so far as I am aware of, has any 

 attempt ever been made to point out its original 



