392 Scientific Litelligence. [Nov. 



called nephin, and uric acid. The term nephrin is systematic, 

 and it has the advantage over vrea of neither being ambiguous 

 nor offensive. 



IV. Laccin. 



I have given this name to a pecuhar substance described 

 some years ago by Dr. John, as one of the constituents of stick 

 lac, though I am not aware that any account of it has hitherto 

 appeared in the English language. It is obtained by digesting 

 stick lac repeatedly in alcohol and water till nothing further can 

 be removed. The. residual matter is laccin. It possesses the 

 following properties : 



It is hard and brittle, has a yellow colour, and a certain degree 

 of transparency. It is insoluble in cold water, but in hot water, 

 though it does not dissolve, it becomes soft. In cold alcohol, it 

 softens, increases in bulk, and acquires a slippery feel. Even 

 hot alcohol is unable to dissolve it. In ether and essential oils 

 it swells a little, and becomes quite transparent, but does not 

 dissolve. It dissolves very readily in potash ley, and the solu- 

 tion has a hght-brown colour. Muriatic acid renders the 

 solution milky, and the laccin slowly precipitates. Concen- 

 trated sulphuric acid dissolves it very rapidly ; the solution has 

 an amethyst colour, and becomes muddy when mixed with 

 water. When long boiled with water containing from ^'^th to 

 |th of its weight of sulphuric acid, only a small portion of it is 

 dissolved. This portion is obtained in the state of a yellowish 

 gum, when the acid is separated by means of lime, and the solu- 

 tion evaporated. This property distinguishes laccin readily from 

 cerasin. Concentrated nitric acid dissolves it slowly when 

 assisted by heat. The solution is clear, and has a yellow colour 

 without any bitter taste. It gradually deposits some crystals of 

 oxahc acid. Diluted nitric acid has no effect on it either cold 

 or hot. 



Laccin, when heated, gives out an aromatic odour, and 

 becomes soft. It does not melt, but is gradually charred. 

 When distilled, it gives out water, an acid which, when satu- 

 rated with soda, throws down muriate of iron white, and a yellow 

 and brown oil. No ammonia can be detected in the products 

 of the distillation. — (John's Chemische Untersuchungen, iv. 12.) 



V. Dry Rot. 



Col. Gibbs, of the United States, is of opinion that the reason 

 why the dry rot is so much more frequent now-a-days than it 

 was formerly, is, that in consequence of the great consumption 

 of wood during the last century for naval and architectural pur- 

 poses, all the old wood has been consumed, and nothing is now 

 left for these purposes but comparatively young wood, in which 

 the albunitun bears a much greater proportion to the heart than 



