148 Scientific Intelligence. [Au». 



Several additional varieties of tremolite have been discovered. 

 This mineral is occasionally so intermixed with the sahlite, that 

 it appears not impossible that the one graduates into the other. 

 Wherever Dr. M'Cullock has observed sahlite in Scotland there 

 tremolite has also been found. 



CrystaUized felspar occurs in veins in the micaceous schist on 

 the hills that form the southern boundary of the Tilt. Adularia is 

 sometimes found in the same cavities. 



Mica, which is not often met with in Scotland in a detached 

 and crystallized state, occurs, however, in the hills so often men- 

 tioned, in three distinct forms of crystallization. It is found 

 imbedded in porphyry, in the form of regular hexagonal prisms, 

 about the tenth of an inch in diameter and length, of a black 

 colour, and with the flat surfaces of the prisms all lying in parallel 

 planes. This parallelism is conformable to a fossile tendency of 

 the including rock, which is also parallel to the sides of the veins, 

 even where it is at right angles with the surrounding strata. 



Chlorite is found in irregular nodules in cavities of micaceous 

 schist, or occupying similar situations in a blue schistose 

 limestone, or like the mica above-mentioned, it is met with in 

 cavities in micaceous schist, occasionally accompanied by crystal- 

 lized felspar. 



Article V. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Fibrous Zeolite. 



Professor Freyssmuth subjected some fine specimens of Wer- 

 ner's fibrous zeolite, recognized to be so by Werner himself, to a 

 careful chemical any lysis. The specific gravity was 2'284. This 

 is the mineral to which Prof. Fuchs has given the name of 

 mesolite. He states its specific gravity to be 2"333. The con- 

 stituents, according to Freyssmuth's analysis, are as follows : 



SiHca 44-562 



Alumina 27-562 



Lime 7-087 



Soda 7-688 



Water 14-125 



Oxide of iron Trace 



101-024 



Professor Freyssmuth considers the chemical constitution of 

 this mineral to be as follows :3AS+ (^So +4.C)S^4- 

 3 A 5- ; that is to say, three atoms of silicate of alumina, one 

 atom of trisilicate of soda-and-hme, and three atoms of water. 



