400 Dr. B. Jones on the Passage of Crystalloids [1865. 



Corresponding angles 

 Found. in Atacamite. 



1 1, 00=63 48' 63 20' 



1 1, 1 0=36 27 36 18 



00, _1 0=56 35 56 10 



1 0, 1 1 = 66 50 67 40 



1, 00=52 50 52 50 



1 1, 1 = 74 20 74 20 



Seen in polarized light through 100, the normal to 1 appears to be a 

 bisectrix, and the plane of the optic axes is parallel to the edge 1 10, 100; 

 and the crystal, as seen through 1 0, is negative. 

 It is dichroic, exhibiting 



C, = plane of polarization parallel to 1, grass-green, 

 b, =plane of polarization parallel to 1 0, more yellowish green. 

 There were but a very few of these minute, in fact microscopic crys- 

 tals ; but two of them I dissolved in nitric acid on a watch-glass, and 

 tested them with nitrate of silver in the field of the microscope. A white 

 cloud was at once struck in the solution, which, while refusing to dissolve 

 in nitric acid, readily yielded to the solvent action of ammonia. This 

 mineral then is Atacamite, as is confirmed by its apple-green streak. Since 

 that time a mine in St. Just has produced this mineral, and I have from 

 Mr. Tailing a specimen from there which contains sulphate as well as 

 chloride of copper. I hope soon to have the opportunity of effecting its 

 analysis from purer specimens than such as have as yet been raised ; for 

 these consist of an intimate mixture, in which Atacamite, indeed, seems to 

 be the preponderating ingredient, but in which, perhaps, Langite and Bro- 

 chantite will prove also to be present. 



" On the Rate of Passage of Crystalloids into and out of the Vas- 

 cular and Non-vascular Textures of the Body." By HENRY 

 BENCE JONES, A.M., M.D., F.R.S. Received April 26, 1865*. 



It occurred to me that possibly, by means of the spectrum, I might 

 trace the rate of passage of medicines into the vascular and non-vascular 

 textures, and prove their presence, and determine the time during which 

 they remain in action in some of the tissues far more accurately than had 

 yet been done. 



I was fortunate enough to obtain the assistance of Dr. A. Dupre, who 

 had already published a paper in the Philosophical Magazine on the 

 presence of lithium and strontium in the waters of London ; and I am 

 greatly indebted to him for carrying out all the suggestions which I thought 

 requisite for proving how soon the salts of lithia pass into the different 

 vascular and non-vascular textures of animals and of man, and how quickly 

 * Read May 4, 1865 ; see Abstract, p. 220. 



