NATURE AND ANALYSIS OF THE POISONS. 121 
4th. A trace of fatty matter. 
5th. Salts, chlorides, and phosphates. 
The color of the venom varied from pale emerald green to 
orange and straw color. 
When the poison had remained long in the gland, it was 
deeper in hue than when its ejection followed rapidly upon 
its formation. In eight observations on record, the venom 
reddened litmus paper more or less distinctly. Jé was wni- 
formly acid, and this reaction was common to all species of 
poison, whether moist or dry, dark-colored, or pale in tint. 
The reaction of the mucous membrane of the mouth was 
almost as constantly alkaline as that of the venom was acid. 
It was found that litmus, reddened by the venom, became 
blue again when left in the serpent’s jaws; but although the 
acid was neutralized, the poisonous properties of the fluid 
remained unaltered. 
In the numerous experiments made by Mitchell, where the 
exhausted yenom-gland was mixed with water, and intro- 
duced into the wounds of various animals, it was ascertained 
that all the pigeons, except one, escaped ; also the rabbit ; all 
the reed-birds died: these latter birds are remarkably sus- 
ceptible to Crotalus venom, and will frequently die from a 
quantity of poison so minute, that it would be hard to con- 
ceive of its power to destroy life, had not the experiment been 
actually made. Thus half a drop will often kill a reed-bird 
‘in a minute or two, and one-eighth of a drop will prove fatal 
after a lapse of from two to eight hours; so that it is proba- 
ble that even a smaller quantity would be sufficient to destroy 
life. 
The secretion in the Crotalus from the gland is constantly 
acid, and in the viper neutral; while the saliva of the parotid, 
in all animals yet examined, is unchangeably alkaline, 
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