216 



M. W. Haidinger on the Colours of Mausite. 



polymeren Isomorphismus/' in Poggendoi-ff's Annalen, as well 

 as Gmelin's Handbook of Chemistry (vol. iii, p. 255), contain 

 full descriptions of the above salt, which was first obtained by 

 Maus*, and which Scheerer for brevity called Maus's saltf, a 

 term which I have here adopted as the root of specific nomen- 

 clature and transformed into Mausite. The difficulty, almost 

 impossibility, of forming a systematic chemical nomenclature 

 will, I think, sufficiently justify the specific name I have pro- 

 posed in the title. 



According to Scheerer, the composition of Mausite is — 

 Sulphuric acid .... 41-94 

 Peroxide of iron . . . 20"97 



Potash 20-58 



Basic water 9 "43 



Water of crystallization . 7*08 

 10000 

 Analyses were made some time ago by Maus, Anthon and 

 W. Richter, and since then by R. Richter in Scheerei-'s labora- 

 tory. The latter analysed not only crystals which were obtained 

 in Scheerer's laboratory, but other larger ones obtained in 

 Schweizer's laboratory at Zurich, by W. Hilgard of Illinois. 



According to a later account, crystals of Mausite may be ob- 

 tained by simply placing a flat vessel containing a solution of 

 common alum-iron in a room at the ordinary temperatui'e, and 

 allowing it there to evaporate. At length Prof. Scheerer sent 

 me a number of small crystals, which, on an immediate exami- 

 nation, exhibit jDroperties so unexpected, that I willingly take 

 advantage of the last meeting in the academical year to commu- 

 nicate my observations to the Mathematical and Physical Class; 

 even before I have had time, from a process of crystallization 

 now in progress, to obtain larger specimens upon which, perhaps, 

 observations may ultimately be made with greater precision. 



In agreement with Scheerer^s desci'iption, the crystals of 

 Mausite are regular hexahedi'al prisms ; those before me measure 

 about half a line in every direction, though many of equal thick- 

 ness and in pei'fectly parallel position group themselves to hexa- 

 hedral tables which measure as much as three lines. Instead of 

 the surface at the end, appears a quite fiat quartzoid. The 

 thickness being half a line, I distin- 

 guish the following tints according to 

 the usual mineralogical nomenclature. 

 Colour of the base hyacinth-red. 

 Colour of the axis E olive-green. The 

 distinction in colour is uncommonly 

 clear, and increases with the thickness. 



* Poggendorff's Annalen, vol. xi. p. 78. 



t Ibid. p. n. 



