THE FAHRENHEIT THERMOMETER 737 



The Fahrenheit thermometer, the measure of temperature 

 still retained by the B.P., and in many works on human 

 materia medica, is the measure again adopted in this book. 

 The Centigrade scale, however, is also extensively used. 

 It is often requisite to ascertain the corresponding numbers 

 on each scale, and for this purpose the following rule is 

 useful. To convert any number of Centigrade into Fahren- 

 heit degrees, multiply by 9, divide by 5, and add 32. For 

 the converse process, subtract 32, multiply by 5, and divide 

 by 9. 



