1839.] Llanean Sorlefy. 19 



March 5 . 



Edward Forster, Esq., V.P., in the Chair. 



Read, " Observations on some Fungi or Agarici, which by de- 

 liquescence form an inky fluid, drying into a bister-coloured mass, 

 capable of being used as a water-colour for drawings, and of a very 

 indestructible nature by means of common agencies." By John 

 Redman Coxe, M.D., formerly Professor of Materia Medica in the 

 University of Pennsylvania. Communicated by the Secretary. 



Dr. Coxe ha\-ing gathered a Fungus and placed it on a sheet of 

 white paper, lea\-ing it until the next day, found several drops of an 

 inky fluid, slowly trickling from the inner surface, which had as- 

 sumed a black appearance ; by placing the Fungus in a glass, the 

 whole except the outer skin liquefied. The colour of the fluid was 

 rather a deep bister than black, and being left in the glass, in a few 

 hours it separated into a solid sediment, with a lighter coloured fluid 

 swimming above. Having afterwards collected a considerable quan- 

 tity of fluid from the same species, he obtained by drying an extract 

 of a pretty deep black colour of both parts conjoined, which would 

 otherwise have sepaiated. This on trial formed an admirable bister- 

 like water-colour, well adapted for drawing when mixed with a little 

 gum. 



Dr. Coxe used the " fresh inky fluid as ink, and from such fresh 

 fluid the accompanying drawings were made ;" but it was soon found 

 that its change was too rapid to think of depending on it for such a 

 purpose, he therefore was led to dry it as quickly as possible by 

 spontaneous evaporation, and then to use it diluted with water. 

 Having exposed various portions of writing thus made to the direct 

 rays of the sun for several months ^\'ith little change, he tried the 

 effects of chlorine and euchlorine gas, muriatic acid, and ammoniacal 

 gases : from these but a trifling change ensued, except from the mu- 

 riatic acid gas, which destroyed very considerably the dark tint of 

 the writings. He also placed some small and recent specimens of the 

 Fungus in a solution of corrosive sublimate, which preserved them 

 and prevented any deliquescence : the same effect was produced bv 

 alcohol. 



The ink is fully formed and escapes in about three or four days. 

 When received into a phial, in a short time the hea\aer and blacker 

 matter was found to settle as a sediment ; the lighter brownish amber- 

 coloured fluid surmounts it, and may be poured off from it to dry them 



