DISSOLVING VIEWS. 



Apparatus for exhibiting the Dissolving Views as shown at the 

 Royal Polytechnic Institution, with the Hydro-Oxygen Light ; or 

 on a smaller scale, suitable for Private use, Schools, &c. illuminated 

 by Patent Argand Lamps, and constructed on the most improved 

 Principles, by T. & R. WILLATS, Opticians, 98, Cheapside, London, 

 who have on hand a large Collection of 



PHANTASMAGORIA AND MAGIC LANTERNS, 



Together with SLIDES for illustrating Lectures on Natural History, 

 Botany, Geology, and Astronomy. 



COMIC SLIDES IN GREAT VARIETY. 



MEDICAL GALVANISM & ELECTRICITY. 



T. &. R. WILLATS respectfully solicit the attention of the 

 Medical Profession to their ELECTRO-MAGNETIC MACHINES, com- 

 bining Compactness, Portability, and Power, as constructed by 

 them for St Thomas's, Guy's, and the principal Metropolitan and 

 Provincial Hospitals, for the application of Medical Electricity. 



Complete in Case, with Battery and Directions, 3. 3s. 



FRICTIONAL ELECTRIC MACHINES, 

 Of every Form and Dimension. 



SMEE'S, DANIELL'S, GROVES', AND CRUICKSHAN K'S 

 BATTERIES. 



CAUSTIC PENCILS AND POINTS. 



URINOMETERS, in CASES, from 4s. 6d. 



