1865.] into and out of the Vascular and Non-vascular Textures. 405 



quantity of lithium in thirty or thirty-two minutes may give traces of 

 lithium in the lens ; but in an old animal in this time it will have got 

 no further than the aqueous humour. If the stomach be empty, in an 

 hour the lithium may be very evident in the outer part of the lens, and 

 very faintly in the inner part ; but if the stomach be full of food, the 

 lithium does not in an hour reach the lens. Even in two hours and a 

 half lithium may be more marked in the outer than in the inner part of 

 the lens. In four hours the lithium may be in every part of the lens, but 

 less evidence of its presence will be obtained there than from the humours 

 of the eye. In eight hours even, the centre of the lens may show less 

 than the outer part. In twenty-six hours the diffusion had taken place 

 equally through every part of the lens. Even one quarter of a grain in 

 twenty-four hours showed lithium everywhere except in the lens. 



Experiment 17. To endeavour to determine the different rate of ab- 

 sorption and excretion in young and old animals, four guinea-pigs were 

 taken ; two were young, and two were old. The four, after fasting for fif- 

 teen hours, were each given two grains of chloride of lithium. Two of 

 them, one young and one old, were killed in six hours. 



The young animal showed lithium distinctly in the outer and inner part 

 of the lens, and also in the cartilage of the hip-joint, when touched with 

 a red-hot wire. The stomach was about half full of food. 



The old one showed lithium distinctly in the outer part of the lens, 

 but scarcely the faintest trace in the inner part. The cartilage of the 

 hip-joint showed lithium quite as distinctly as the cartilage of the young 



Pig- 



The other two guinea-pigs were kept. After forty-eight hours, the 

 urine of both showed lithium very distinctly in one drop. Six days after- 

 wards, the urine of the young animal still showed lithium faintly in each 

 drop. The urine of the old one found in the bladder after its death 

 showed lithium faintly in each drop. 



Both were killed on the sixth day, and no lithium could be detected in 

 the alcoholic extracts of the kidneys, livers, or lenses of either. 



A short series of experiments were made with the view of determining 

 the rate at which the salts of lithium diffuse into the textures when 

 the lithium is injected into the skin instead of passing through the 

 stomach. 



Three grains of chloride of lithium in solution were injected into the 

 skin of the back of the neck of a guinea-pig, and the animal was killed in 

 twenty-four minutes. 



The urine, bile, kidney, and liver showed lithium very distinctly. The 

 cartilage of the hip-joint showed lithium distinctly when touched with 

 a red-hot wire. The aqueous humour showed lithium very distinctly, 

 but the lens, when washed, showed only a very minute trace ot lithium 

 when the entire lens was taken at one time on the wire. The toe-nails 

 showed lithium very distinctly. 



VOL, XIV. 2 H 



