38 REPORT— 1861. 



On the Medicinal Mwls of the Island of Ischia, Bay of JSfajyles^ 

 By Dr. T. L. Pnirsox, FX'.S. Land. 



Two specimens of these muds were forwarded, not long ago, to my laboratory. 

 Invalids visiting IscLia plunge their aims, legs, or entire bodies into them, for various 

 diseases, more particularly for scrofula and rheiunatism. One of the bottles con- 

 taining these muds was ticketed Fmujo di GurijiteUn, the other Fango del Aritfa, 

 They diifer very much in appearance and in smell, though they are essentially the 

 same in composition and properties, being formed of volcanic or felspathic gTains. 

 The whole constitutes a volcanic sand rendered muddy by water, and a certain 

 quantity of vegetable debris. The grains are composed of lava, green felspar, 

 ryacolite in beautiful glassy grains, augite, quartz, mica, here and there a few grains 

 of marble, &c. 



My analysis of these muds gives them the following composition : — 



Fango di Gurgitella. \ Fango del Aritta. 



Greenish grey ; no smell ; insipid ; j Black ; smell of putrid Algae and 

 sandy, with little mud. Deposits sul- \ sulphm-etted hydrogen. Gives PbS on 

 phur on a plate of silver in twenty-four , paper imbibed with acetate of lead, 

 houi-s. \ when heated. 



Water 30-00 [ AVater 42-85 



Organic matter 4-00 , Organic matter 4-05 



Oxide of iron 1-40 , Black sulphide of iron 1-36 



Carbonate of lime 1-20 j Oxide of iron 2-00 



Bromine and iodine none j Carbonate of lime 2-60 



Sulphui- traces i Bromine and iodine none 



Volcanic? sand as above described 63-40 ^ Sulphm- distinct traces 



Volcanic sand as above described 47-14 



100-00 



10000 



The Italian bottles in which these specimens of the Ischia muds were forwarded 

 to me, though corked with large glass stoppers, do not close hermetically ; and I have 

 no doubt that tlie water of these muds, in its natural state, is strongly impregnated 

 ■with sulphuretted hydrogen, which has almost entirely escaped from the samples 

 during the journey. The black colour of the Fango del Aritta is owing to a layer 

 of black sulphide of iron, foi-med by the action of sulphuretted hydi'ogen upon the 

 grains of green felspar, which it envelopes completely. "When the mud is exposed 

 to the air for some time, the black sulphide is gi-adually oxidized, and the grains 

 assume their original green colour ; in this manner the Fango del Aritta becomes 

 similar to the Fango di Gurgitella. 



It is remarkable that sulphuretted hydrogen, like carbonic and sidphurous acids, 

 attacks the iron of the felspar rocks in preference to the alkalies, which are not 

 attacked at all, for the glassy grains of ryacolite have undergone no decomposition 

 whatever. Diluted hydrochlonc acid dissolves this black sulphide of iron, formed 

 on the sm-face of the green grains, with evolution of sulphuretted hydrogen gas. 

 No iodine or bromine was detected ill either of the muds ; but, by passing a mag- 

 net through some of the Aritta mud, a number of brilliant black grains, which were 

 proved to be magnetic oxide of iron, were extracted from it. The water separated 

 by filtration from the sand, and merely gave indications of lime, sulphuric acid, and 

 chlorine, and did not ditier from ordinary river-water in composition, except by the 

 presence of a small proportion of free sulphuretted hydi-ogen gas, which in that of 

 the Fango del Aritta ouly amoimted to ^ ^^-,"^^^ ths, but I believe the greater por- 

 tion of this gas had escaped during the journey. 



The curious custom of plimging the body into muds of this kind, as a means of 

 restoring health, is not confined to the island of Ischia. I have lately found that 

 a similar custom prevails in the neighbourhood of the Salt Lake, Balta Alba, in 

 the Danubian provinces ; and I have heard that the same practice was once resorted 

 to in the south of England. 



The beneficial effects that are said to follow such treatment are probably owing 

 as much to the cleansing and stimtdating effect produced by the friction of the grains 



i 



