1012 
PROFESSOR J. W. MALLET ON A REVISION 
Or, if we throw together only the numbers obtained by Tissier and Terreil, which 
come nearest to each other, we have— 
Tissier. 27 - 068 
Terreil. 27-030 
Mean.27'049 
Berzelius. 27’237 
Dumas (mean). . . . 27'462 
Values now generally adopted for atomic weight of aluminum. 
The number adopted in some of the more recent chemical handbooks, reports, &c., 
may be quoted as follows :— 
Gmelin : ‘Handbook of Chemistry’ (Cav. Soc. Trans.) . . . 27'4 
Watts: ‘ Dictionary of Chemistry,’ First Supplement. . . . 27 - 4 
W. A. Miller : ‘ Elements of Chemistry,’ 4th edit.27'5 
Meymott Tidy : ‘ Handbook of Modern Chemistry’ . . . . 27’5 
Frankland : ‘ Lecture Notes for Chemical Students’ . . . . 27'5 
Thorpe: ‘ Quantitative Chemical Analysis’.27‘26 
‘Agenda du Chimiste’ (Wurtz’ Laboratory, 1879). 27 - 5 
‘ Annuaire du Bureau des Longitudes, 1876’.27‘4 
Naquet: ‘ Principes de Chimie,’ &c., 3 e ed.27'5 
Fittica : ‘Jahresb. lib. d. Fortsch. d. Ch'emie, 1878’ . . . . 27 - 4 
PtOSCOE u. Schorlemmer : ‘ Ausf. Lehrbuch d. Chemie’ (Ger. ed.) 27 - 3 
Fresenius : ‘Anleit. z. quant, chern. Analyse,’ 5 tp Aufl. . . . 27 - 5 
Classen : ‘Grundr. d. anal. Chemie’ (quant.).27'3 
Kohlrausch : ‘Leitfaden d. prakt. Physik,’ 2 te Aufl.27'4 
Mendelejeff : Paper on the “ Periodic Law” (transl.) . . . 27‘3 
J. P. Cooke, Jr. : ‘The New Chemistry’.27'5 
J. D. Dana : ‘ System of Mineralogy,’ 5th ed.27'5 
E. S. Dana: ‘Text-Book of Mineralogy’.27'3 
New experiments by the author. 
During the last three years I have devoted a large part of my leisure time to a 
re-determination of this atomic weight, sparing no pains to attain as precise a result 
as possible, and aiming especially at the discovery, and as far as possible removal, 
of sources of error connected with the methods employed. The following general 
principles have been kept in view :— 
