146 Liniiccan Socielij. 



is not known to exist in tlie merorganized state, except tlie acid 

 found in almost all animal matters, and hitherto called the lactic 

 acid, be deserving of that appellation. 



The woody fibre, or liguin, was the last substance belonging to 

 this series, which was considered ; and in proof of its alimentary 

 qualities, the author quoted the experiments of Prof. Antenrieth, 

 showing it to be capable, by certain processes, of acquiring the pro- 

 perty of gelatinizing like starch when boiled in water, and also of 

 forming bread. Sugar of milk, manna, and gum, were next con- 

 sidered, and afterwards the oxalic, citric, tartaric, and saccholactic 

 acids, the composition of all which was stated; and the author 

 concluded by observing that he refrained purposely from chemical 

 observations on the subject, until all the facts in his possession were 

 laid before the Society. 



LINNiEAN SOCIETY. 



June 5. — A paper was read, entitled, " Observations and experi- 

 ments made with a view to ascertain the means by which the spiders 

 that produce gossamer effect their aerial excursions ; by John Black- 

 wall, Esq. F.L.S. of Crumpsall Hall near Manchester." 



After noticing that in the absence of accurate observation the 

 ascent of gossamer spiders through the atmosphere had been con- 

 jecturally ascribed to several causes, such as the agency of winds, 

 evaporation, electricity, or some peculiar physical powers of the 

 insects, or from their webs being lighter than the air, Mr. Black- 

 wall states that the ascent of gossamer takes place only in serene 

 bright weather, and is invariably preceded by gossamer on the 

 ground. He then details the phaenomena of a remarkable ascent of 

 gossamer, Oct. 1, 1826, when a little before noon the ground was 

 everywhere covered with it, the day being calm and sunny. A vast 

 quantity of the fine shining lines were then seen in the act of ascend- 

 ing, and becoming attached to each other in various ways in their 

 motion, and were evidently not formed in the air but on the earth, 

 and carried up by the ascending current caused by the rarefaction 

 near the heated ground ; and when this had ceased in tlie afternoon, 

 they were perceived to fall. An account is added of two minute 

 spiders that produce gossamer, and of their mode of spinning, and 

 particularly when, impelled by the desire of traversing the air, they 

 climb to the sunnnits of various objects, and thence emit the viscous 

 threads in such a manner as that it may be drawn out to a great 

 length and fineness by the ascending current, until, feeling them- 

 selves sufficiently acted upon by it, thej' quit hold of the objects 

 on which they stood, and commence their flight. Some of these 

 insects, which were taken for the purpose of observation, when ex- 

 posed to a slight current of air, always turned the thorax to the 

 quarter from whence it came, and emitted a portion of glutinous 

 matter, which was carried out into a line. 



June 19. — Descriptions were read of two quadrupeds inhabiting 

 the South of Africa, about the Cape of Good Hope; by Andrew 

 Smith, M.D. Superintendent of the South African Museum, As- 

 sistant Surgeon to the Forces. 



1 The 



