262 Scientific Intelligence. 
readily becomes transparent when placed in water. Almost any foreign 
substance present suffices to determine the quartz to assume the char- 
acter of hydrophane. , 
17. Test for Manganese ; by Wauter Crum, (Annalen des Chem. 
und Pharm., August, 1845, p. 219.)—If peroxyd of lead be heated 
with dilute nitric acid, and there be added to it a solution of manganese, 
the liquid acquires the purplish-red color of permanganic acid, which 
is readily perceived as soon as the excess of peroxide has subsided. 
This is an extremely = test—by means of it a white marble was . 
found to contain mang Jel Se 
18. Valerianic aie ia the Chem. Gazette, January 1, 1846, 
p- 9.)—The berries of the Viburnum opulus afford a volatile acid, which 
was called phocenic acid, by Chevreul, but afterwards was shown by 
Dumas to be identical with valerianic acid. L. von — has con- 
firmed the view of Dumas. 
19. Atomic weight of Uranium; (Pogg. Ann., Ixvi, 91, 1845.)— 
Experiments by RamMEtsBERG, go to show that the weight of uranium 
is between 725 and 750, thus confirming the results of Wertheim and 
Ebelman, the former of whom obtained the number 746°36, by the 
analysis of the crystallized acetate of soda and uranium, and the latter 
742-875, from the oxalate of uranium. 
20. Eudiometry ; (Chem. Gaz., January 1, 1846, p- 23.)—Prof. 
GraHam recommends, for the rapid absorption of oxygen in the eudio- 
metric process, a solution in ammonia of a sulphate of the suboxide of 
copper and ammonia. This salt falls as a brown powder when @ 
stream of sulphurous acid gas is conveyed into a cold ‘solution of the 
ammoniacal sulphate of copper. When dissolved in ammonia, it absorbs 
oxygen with singular avidity ; and when employed in this form in eudi- 
ometry, gives results of considerable uniformity. 
21. Detection of Poisons by Physiological Tests ; (Buchner’s Re- 
port, xxxvii, 8, and Chemist, July, 1845, p. 316.)—The eye is so deli- 
eate a test for atropine, (the alkaline principle of belladonna,) that, 
according to Rieck, :o/55 of a grain dissolved in water and applied to 
the eye of a rabbit, produces dilatation of the pupil ; and even yoov00 
of a grain, after having been twice applied to the eye, produces the 
same effect. Runge found that this alkaloid, as well as hyoscyamine, 
is evacuated by the urinary organs, and that the urine of rabbits, after 
they had taken either belladonna, stramonium or hyoscyamus, on being 
applied to the eyes of other animals, invariably produced a dilatation of 
the pupil. 
- It is known that sheath and brucine are dietineiiehgil from all 
other alkaloids by the fact, that on being applied in very small quanti- 
ties to a vein or fresh wound, they produce most violent irritation’ of 
