(78) 
MARKOWNIKOFF !), EMELJANOW °), Eov. Hseit*), HOEVELER *), STOCK- 
MEIER °) and SCcHAUM °). 
The phenomenon has been observed on articles made of tin such 
as organ pipes, buttons of uniforms, coffee pots, medais, rings ete. 
and not only on blocks of pure Banca tin. 
Whilst tin in the ordinary, well known condition, is silver-white, 
it becomes grey under certain circumstances and loses its coherence. 
2. The different authors by no means agree as to the cause of 
the change. 
Some ascribe the change to great cold, others to the combined 
influence of cold and vibration, whilst a third group of observers speak 
somewhat vaguely of an influence which the greater or smaller rate 
of cooling of the tin after it had been melted might exert on the 
occurrence of the phenomenon. 
3. FRITZSCHE proved qualitatively that a considerable expansion 
accompanies the transformation of the silver-white into the grey 
condition. SCHERTEL and RAMMELSBERG found later that the specific 
gravity of the grey modification at 19° is about 5,8 whilst the 
silver-white form at the same temperature has the specific gravity 7,3. 
4. The facts enumerated remained up to the present isolated ; 
many points in the different memoirs could not be brought into 
harmony with each other. 
A more accurate, quantitive treatment of the subject, based on 
the newer physico-chemical conceptions, may perhays throw some 
light upon it; at the request of Prof. Baknuis Roozesoom we have 
undertaken this and give in what follows a very brief account of 
some of the results thus far obtained. 
5. The material used was obtained from Prof. Epv. Hseir of 
Helsingfors, who was kind enough to send us 25 grams of grey tin. 
This tin was part of a piece of Banca-tin which had falien into 
powder in the warehouse of a Helsingfors firm. 
1) Journ. russ. phys. chem. Gesellschaft 1881, 358; Bulletin de la Société chimique 
de Paris (2) 37, 347 (1882). 
2) Congress russischer Naturforscher und Aerzte Petersburg 1890. 
3) Chemiker Zeitung 16, 1197 (1892); vOfversigt af Finska Vetensk. Soc. för- 
handlin”. 32. 
*) Chem. Zeitung 1892. 1339. 
*) Verh. d. Ges. Deut. Naturf. u. Aerzte. Nürnberg 1893. 
5) Die Arten der Tsomerie. Habilitationssehrift, Marburg 1897, 
