EFFECTS OF DRUGS ON WHITE MICE 137 
The nicotine line 
The first generation in this line consisted of 6 females and 3 
males, and the second generation, the offspring of the first, of 
3 females and 2 males. 
This line had 2 ee. per mouse of 1:1000 nicotine solution added 
to their crackers and milk daily, and the same solution was sub- 
stituted for drinking water in bottles with siphons. Different 
strengths of nicotine had been tested on white mice from 1:2000 
to 1:500 solution. The last was fatal but on 1:1000 they remained 
in good health, although this solution was found to kill grey rats 
in nine days. 
All the mice in this line except 6 received nicotine, the young 
beginning to take it at the age of three weeks. Six young were 
given no nicotine themselves although their mothers received it 
for sixteen days after the birth of the young. 
The line subjected to the fumes of tobacco 
The first generation in this line consisted of 6 females and 3 
males, and the second generation, the offspring of the first, of 
8 females and 4 males. | 
These mice were subjected to tobacco smoke for about five 
minutes at a time and then aired for five or ten minutes; this 
was repeated for two hours each day. The smoke chamber was 
a bell jar made air tight by being placed on glass and moistened 
around the bottom. About 4 grams of Connecticut leaf tobacco 
were burned each day in a clay pipe inserted in a rubber cork in 
the top of the bell jar. The smoke was drawn through the jar 
by an air pump, the tube for this purpose being in the rubber cork. 
All the mice of this line except 9 were subjected to the fumes of 
tobacco, the young being put in the smoke chamber from the time 
they were a few days old. Nine young were not subjected to the 
fumes of tocacco, although their mothers were each day while 
they were suckling. 
