218 Account of a remarkable case of Spectral Illusion. 



Another species of Wad, of the exact locality of which I am 

 ignorant, was lately sent me from Germany, under the name 

 of ochreous Wad, by Professor Hausmann. It is a friable 

 earthy substance, like the foregoing species ; but the colour of 

 its streak and powder is dark or blackish brown. It is very 

 porous, and emits a copious stream of air-bells when put 

 into water. Its specific gravity is 4.506. 



On exposure to a red heat, after being dried at. a tempera- 

 ture of 212*^ F., it loses 3.08 per cent, of water, together with 

 oxygen gas. Its loss at a white heat amounted to 12.755 per 

 cent. ; namely, 3.08 of water, and 9.675 of oxygen. In mu- 

 riatic acid it is readily dissolved with free disengagement of 

 chlorine, leaving merely traces of insoluble matter. The solu- 

 tion was free from lirne and iron, but contained a trace of 

 baryta. Considering its high specific gravity, the small quan- 

 tity of combined water, and the large quantity of oxygen, 

 which it loses at a white heat, there cannot be a doubt that 

 this species of wad consists essentially of the anhydrous per- 

 oxide of manganese, with which a small quantity of some hy- 

 drated oxide, probably manganite, is casually intermixed. 



Art. IV. — Account of a remarkable case of Spectral Illusion, 

 in which both the Eye and the Ear were influenced. * In a 

 Letter to the Editor. 



Those who have read Dr Hibbert''s admirable work on the 

 Philosophy of Apparitions, and have appreciated the ingenious 

 views which he has taken of this remarkable class of mental 

 phenomena, will peruse with double interest the very singular 

 case of spectral illusion which forms the subject of this paper. 

 It was communicated to me by the gentleman whose lady 

 was under its influence, and who was himself present during 

 the whole progress of the illusion which affected the eye. 

 Were I permitted to mention his name ; — his station in society, 

 and as a man of science, would authenticate the minutest par- 

 ticulars in the following narrative, and satisfy the most scru- 

 pulous reader that the case has been philosophically as well as 

 faithfully described. The gentlejman and lady, indeed, were 



• Since this sheet was put in types we have received another interest- 

 ing case, which will form a subsequent article in this Number. — Ed. 



