863 Captain Hall's Notice of a Voyage of Research. 



There are other parallels in higher latitudes, where, if it were 

 •necessary, these experiments might be repeated, but none which 

 offers such conveniencies as the above. 



It will readily be admitted by practical men, that such an ar- 

 duous course of service could only be properly executed by an 

 .officer whose sole duty it should be to devote his time and thoughts 

 ,to its accomplishment. He would require to be supported by 

 numerous and able assistants, and be left in a great measure to 

 the exercise of his own discretion as to the details of the voyage, 

 such as the ports he should touch at, and the periods of his stay 

 at each. As it is well known that the ordinary course of naval 

 duties on foreign stations, occupies the whole of the commanding 

 officer's time, it would be essential to the success of any such 

 voyage as this, that the commander should be left quite free, as 

 far as the nature of the service would allow, from all extraneous 

 duties unconnected with these objects. In war this is impossi- 

 ble, — ^in peace it is easy ; and this is the only time, therefore, 

 that such an enterprise can be thought of. 



On Achmite, Hyalosiderite and Trachylyte. 

 Breithaupt of Freyberg. 



I. Achmite. 



By Professor 



X ROFEssoR MiTscHERLiCH, in Schweigger''s Journal of Che- 

 mistry, describes the Achmite, a Norwegian mineral, as a new 

 species. On reading his account, I was immediately struck with 

 the resemblance of this mineral to Augite. I soon had an op- 

 portunity of examining a small suite of this mineral, in the col- 

 lection of Heyer in Dresden, and was convinced that Achmite 

 was a mere variety of Augite. I could not find those differences 



