INTRODUCTION. 3 



tions cannot be easily answered in a table of this sort. In order to 

 relieve this difficulty, the references to original papers have been sup- 

 plied. Almost every determination in the tables is accompanied by 

 such a reference. Some of these, indeed, are not direct references to 

 the paper of the investigator, but to the "Jahre^bericht," by means of 

 which, however, the paper itself can be found. Some determinations, 

 nevertheless, lack such references. They were among those which 

 formed the first table, compiled for private use, and which I have not 

 hien able since to trace back to their sources. 



In conclusion, a brief statement of the extent of the work here 

 presented may be desirable. The table, exclusive of its supplement, 

 contains the specific gravities of 2263 substances, and over 5000 deter- 

 minations in all. There are over 2000 determinations of boiling point, 

 representing 1205 different substances; and nearly 500 of melting point, 

 for 326 different substances. In all, the names of 2572 distinct bodies 

 will be found in the table. The work may contain errors — especially 

 errors of judgment in arranging the material — but the writer hopes 

 that these are few in number. And he feels sure that all who have 

 experienced the difficulties of preparing such work for the press, will 

 readily pardon the mistakes which may have occurred. 



F. W. C. 



Boston, April 14th, 1872. 



