354 Zoological Collections. 



some time, but was again abandoned on account of the bad 

 quality of the antimony extracted. M. Berthier has imagined 

 the following process, by which the metal obtained becomes 

 perfectly pure. The mineral, without previous roasting, is to 

 be melted with about one-third, or a little less, of its weight of 

 metallic iron, to which is added a small quantity of sulphate of 

 soda mixed with charcoal. 



In regard to its external appearance, Berthierite much re- 

 sembles some of the other species of the genus antimony-glance, 

 as the common grey antimony, and the Jamesonite, and also the 

 zinkenite. It occjurs in elongated imbedded prisms, with a 

 single pretty distinct longitudinal cleavage. Its colour is a 

 dark steel-grey, inclining to pinchbeck-brown, with a metallic 

 lustre. These properties are not sufficient to characterize the 

 mineral. A future number of this Journal will contain an 

 exact account of all of them. 



Art. XXXIII.— zoological COLLECTIONS. 



1. On the Change in the Plumage of some Hen- Pheasants ' By. W. 

 Yahrell, Esq. F. L. S. 



The last shooting season having been unusually productive of hen phea- 

 sants, which have assumed more or less the plumage and appearance of the 

 male, much discussion has in consequence arisen on the cause of this 

 change ; and the author, having had many opportunities of examining the 

 facts, as respecting both the pheasant and the domestic fowl, was induced 

 to notice the internal peculiarities which invariably accompany this trans- 

 formation. According to an opinion of John Hunter and Dr Butter, this 

 change only takes place at an advanced age ; but Mr Yarrell considers the 

 facts in his possession as at variance with this idea, and that the appear- 

 ances in question may occur at any period of life, and may even be pro- 

 duced artificially. 



In all the instances examined by him the sexual organs were found dis- 

 eased, and to a greater or less extent in proportion with the change of 

 plumage. The ovarium was shrunk, purple, and hard. The oviduct dis- 

 eased, and the canal obliterated at the upper part, immediately preceding 

 its infundibuliforra enlargement at the bottom of the ovarium. Having 

 opened a hen pheasant in her natural plumage for the sake of comparison, 

 he found a similar diseased state of the organs to exist, thus proving that 

 the disease must exist some time before the corresponding change of fea- 

 ther takes place. He observes, that it is no uncom.mon thing to find 

 among numerous broods of pheasants reared by hand, some females, which. 



