142 



ELEMENTS OF LABORATORY WORK 



of chemical combination, which has been called the law of 

 combination in multiple proportions, will be found among 

 compounds containing carbon. The following table gives a 

 number of distinct compounds, containing only carbon and 

 hydrogen. The relative quantities of these elements in each 

 compound vary in the manner indicated. The Atomic Theory 

 will be found to give a reasonable explanation of these 

 relations, and also of the formulae by which the different kinds 

 of matter are denoted. The distinctness of the substances 

 is indicated by the difference in such physical properties as 

 density, melting-point, and boiling-point. 



Table of Homologous Paraffins. 



Bodies containing Carbon and Hydrogen united 

 Relative Quantities. 



different 



94. The Rise in Temperature during Chemical Combina- 

 tion. A quantity of sulphur is allowed to burn in oxygen and 

 form sulphur dioxide. The sulphur dioxide thus formed is at 

 a temperature much higher than that of the sulphur or oxygen. 

 The magnitude of this thermal change is approximately 

 measured by the change in temperature of a known quantity 



