1S4 Description of Pehkonite, 



taking the quantity of blood in the adult person at 30 lb. 

 amounts to nearly 8.5 lb. water, and 47 grains of acetic acid. 



Mr Hermann conceives that it is principally in consequence 

 of the removal of acetic acid from the blood, that the fibrinous 

 polypous concretions arise in the cavities of the heart. In the 

 healthy condition of the blood, he says that the acetic acid acts 

 as a solvent to the fibrine ; but, when a large proportion of it is 

 removed, along with the vomited and purged matter, there arise 

 these polypous concretions, which Dr Jahnichen invariably found 

 in the cavities of the heart, in fifty bodies of cholera patients, 

 which he dissected. 



He also states, in confirmation of this opinion, that the altera- 

 tion in the composition of the blood, does not occur till after 

 there have been watery evacuations by vomiting or stool ; and 

 that the concretions of fibrine are much firmer, and more com- 

 pact in those patients who linger for some time, than in those 

 who die suddenly. 



At the conclusion of his paper, Mr Hermann brings forward 

 a theory of nervous excitement to account for the production 

 of the changes previously mentioned to take place in the fluids 

 and secretions of the body during cholera, and ends with a pro- 

 posal for treatment founded on the chemical views given, — the 

 injection of water into the veins being one of the remedies which 

 he proposes. 



Description of Pelohonite.^ By G. F. Richter, in Freyberg. 



r'oRM, unknown; cleavage, none;yrac^wr^, conchoidal; colour, 

 bluish-black ; streali, liver-brown ; opaque ; lustre, vitreous, 

 feeble, almost dull ; tenacity, not great ; hardness, 3.0 (that of 

 calc spar) ; specific gravity, 2.509, and a larger fragment 2.567. 

 The pelokonite is found in the Tierra Amarilla, and the Remo- 

 linos in Chili, along with copper- green, malachite, and another 

 unknown blackish-brown mineral with a yellow streak. 



This mineral is not noticed in the mineralogical manuals. 

 In Dr A. Breithaupt's " Characteristik des Mineral Systems,'' 



• From TiXos brown, and xovis dust, the powder of the streak, to distinguish 

 it from copper and manganese ore. 



