363 



Monday, March 17, 1856. 



Right Rev. BISHOP TERROT, V.R, in the Chair. 



The following Communications were read ; — 



1. An Account of some Experiments on certain Sea- Weeds 

 of an Edible kind. By John Davy, M.D., F.R.S., Lond. 

 and Edin., &c. 



The sea-weeds examined by the author, reported on in this paper, 

 were the following : — Carrigeen Moss {Chondrus crispus), Dulse or 

 Dylisk {Mhodymenia palmata), Sloke or Laver {Povphyra laci- 

 niata). Tangle {Laminaria digitata), Doughlaghman {^Fucus vesi- 

 culosus). 



The results, imperfect as they are, it is stated, are oflPered as a 

 contribution, with the hope of inducing others more favourably 

 situated to turn their attention to a subject hitherto, in a chemical 

 point of view, singularly neglected. 



Chondrus crispus was found to be composed of about 28*5 parts 

 by weight soluble in cold water, of 49 soluble in boiling water, and 

 of about 22*5 per cent, resisting both infusion and decoction. The 

 part dissolved by boiling water had the properties of gelatine ; that 

 by cold water of mucilage. 



In Dulse no gelatine was detected. Acted on by cold, followed 

 by boiUng water, it lost about 52 per cent. Its colouring matter has 

 the property of combining with alumina, and is precipitated by this 

 earth from its infusion. 



Sloke or Laver was found to be very similar to the preceding. 

 Acted on by cold and by boiling water it lost about 50 per cent. 



Tangle also bore a considerable resemblance to the preceding, 

 judging from the properties of its infusion and decoction. The stalk 

 yielded less soluble matter to water than the fronds, only about 13-5 

 per cent. 



Fucus vesiculosus lost by infusion about 16 per cent., and by sub- 

 sequent decoction about 39 per cent. 



In all these Algse iodine was detected in the matter extracted by 

 infusion and decoction, and in the residual matter : it was found also 

 in the water used to wash the weeds, for the purpose of removing 



