J. W. Langley —Chemical Affinity. 361 
is again bathed with light which comes from all directions. 
This partial arrest may even arise from the plant itself, as 
when the excessive growth of the vine in forming new wood 
saps the energy which should go to the formation of fruit, and 
the grapes, which alone make the plant valuable to man, never 
‘reach that fullness and flavor which should recompense the 
toil of the husbandman. 
__All of us here are constituent intellectual atoms in a great 
ideal organism called Chemistry. We know the long and hon- 
orable history of our science, we know too its wonderful 
delight, and which stand forth as the declared fruit of our toil. 
Such a fruit bud our science put forth in its alchemical 
stage under the name of affinity. During the early part of the 
present century the idea received considerable expansion and 
showed at one time a vitality comparable with the condition of 
the doctrine of the conservation of energy prior 
affinity seems to have been arrested and soon it is seen occu- 
nterest to chemists. 
The proof of this statement is easily found by comparing such 
works as Daniel’s Introduction to Chemical Philosophy, 
Thompson’s History of Chemistry and Daubeny’s Atomic 
Theory, published in 1830 and ’31, or the works of Berzelius, 
with any recent manual of inorganic chemistry. In the older 
books 16 amount of space given to the treatment of chemical 
affinity is relatively large, while in the treatises of to-day it 1s 
in many cases hardly even mentioned. ; 
In the article Chemistry, in the new Encyclopedia Britan- 
‘nica, covering 120 pages, tee is not a single paragraph referred — 
