ABSORPTION OF NITROUS GA#. IOJ 



EXPLANATION OF THE FIGURES. Plate VI. 



Fig. 1 mews the external ear, the meatus auditorius, mem- 

 brana tympani, and Euftachian tube. 



A, the meatus. 



B, the membrana tympani. 



C, the cavity of the tympanum. 



D, the Euftachian tube. 



Fig. Q (hews the perforating inftrument as it is introduced 

 in the operation. 



Fig. 3 the membrana tympani of Mr. G , of which 



only that part which appears of a lighter colour remains. 



Fig. 4 the membrane lacerated by a blow. 



Fig. 5 the membrane lacerated in an attempt to extract a 

 pin. 



Fig. 6 thews the membrana tympani of a medical man in 

 the city, having a fungus projecting through it. In this ear 

 he is confiderably deaf. 



Fig. 7 the other membrane of the fame gentleman. 



Fig. 8 one of the memhranes of Mr. P , whofe cafe „ 



was defcribed in the former paper. 



Fig. 9. A membrana tympani in its natural ftate, the wing 

 the attachment of the manubrium to the malleus. 



Fig. 10 the appearance of the membrane after having been 

 punctured. 



VI. 



Note refpeSting the Abforption of Nitrous Gas, by Solutions of 

 Green Sulphate and Muriate of Iron. By Mr. H. Davy, 

 Director of the Laboratory, and Lecturer on Chemifiry to the 

 Royal Inftitution.—( From the Author.) 



W HEN nitrous gas is brought in contact with folution of Solution of 

 green fulphate, or green muriate, of iron, it is rapidly ab- ^muriate of** 

 forbed ; the colour of the fluid alters ; and it becomes, when iron, abforbs ni« 

 faturated with the gas, dark brown, and almoft opaque. trous gas > 



Solution of fulphate, or muriate, of iron, impregnated with and undergoes 

 nitrous gas, apparently undergoes no change at low tempera- no chan 8 e at 

 lures, when preserved from the contact of the atmofphere. t ure*. 



But 



