468 Scientific Notices — Mineralogy. [Dec. 



interesting mineral, sent to him for this purpose by Dr. Brews- 

 ter, obtained the following results : 



Carbonate of lead 71*1 



Sulphate of lead 30-0 



Muriatic acid Trace 



Lime Trace 



101-1 



In the letter with which M. Berzelius has favoured us on this 

 subject, he remarks, that his result accords with that of Mr. Ir- 

 ving, of Edinburgh, who found the carbonate of lead to be 73, 

 and the sulphate 29, giving an excess of 2*0. — (Edin. Phil. Jour, 

 vol. vi. p. 388.) He likewise remarks, that as he had an excess 

 of 1-1 of weight of the stone, it is probable that a part of the 

 oxide of lead in it is in the form of a subsalt. " The result," he 

 adds, " as it is, does not agree with the definite proportions ; 

 and the small quantity of the mineral did not permit me to make 

 idterior experiments." 



Mr. Brooke, in his analysis, makes the results agree perfectly 

 with the definite proportions (Edin. Jour. iii. 118), viz. about 

 72"5 of carbonate, and 27 - o of sulphate of lead. He had no 

 excess of weight, and did not observe either the trace of muriatic 

 acid or of lime. — (Edin. Jour, of Science.) 



Mineralogy. 



3. Localities of Scottish Minerals. 



In No. 2 of the Edinburgh Journal of Science, Dr. Maccul- 

 loch has given a list of localities of some Scottish minerals. 

 Among these several of the substances which formerly belonged 

 to the zeolite family, are incorrectly named. Under Stilbite 

 Dr. M. includes a red mineral from Kilpatrick Hills, and a 

 colourless or slightly tinged substance found at Strontian. These 

 minerals differ essentially from each other in their specific 

 characters. The first is described in Phillips's Mineralogy, 

 under the name of Heulandiie, and the second as Brewslerite. 



In reference to Comptonite, Dr. M. says, " If this be a new 

 mineral, it is the supposed stilbite of Strontian ; " that is, it is 

 not a new mineral. But if Dr. M. had ever examined Compton- 

 ite, and compared it with Brewsterite, he would have found 

 sufficiently marked distinctions between them to have prevented 

 his confounding them with each other ; and he would also have 

 ascertained that Comptonite differed from every other known 

 mineral. 



Among the localities of Nadehtein, Dr. M. refers to Kilpa- 

 trick Hills, and he also includes under this species the natrulite 

 from Staffa. 



It is evident that Dr. M. has looked at this tribe of minerals 



