cane-sugar solution produced no fermentation whatever when poisoned with a small quantity of arsenious acid; with oil of turpentine, and creasote, similar negative results were obtained.  The introduction of cream-of-tartar along with the arsenic neutralised its effect, but not so with the other two; and, singularly enough, the appearance of the liquor always shewed when the poisoning was complete; ’the nitrogenous layer on the cell-membrane seeming to have undergone a change similar to that produced by boiling.’  Judging from the results, Professor Erni believes ’that alcoholic fermentation is caused by the development of fungi.  He could never trace the process without observing at the very first evolution of carbonic acid, the formation of yeast-cells, although it is very difficult to decide certainly which precedes the other.’  His own opinion is in favour of the commencement by the yeast-cells.

Another noteworthy subject, is Dr W.J.  Burnett’s paper to the American Association, ’On the Relation of the Distribution of Lice to the Different Faunas,’ in which he endeavours to demonstrate, that the creation of animals was a multiplied operation, carried on in several localities, and that they do not derive from one original parent stock.  Different animals have different parasites; but, as he shews, the same species of animal has the same parasite, wherever it may be found.  According to Latreille, the pediculus found in the woolly heads of African negroes ’is sufficiently distinct from that of the Circassian to entitle it to the rank of a distinct species;’ from which, and similar instances, the doctor concludes:  ’Whatever may be urged in behalf of the hypothesis of the unity of the animal creation, based upon the alleged metamorphosic changes of types, it is my opinion that the relations of their parasites, and especially the lice which are distributed over nearly all of them, must be considered as fair and full an argument as can be advanced against such hypothesis, for it is taking up the very premises of the hypothesis in opposition.’  Dr Burnett will perhaps find Sir Charles Lyell ready to break a lance with him on the point at issue.

Something interesting to workers in metal has been brought before the Franklin Institute at Philadelphia—­it is a method of giving to iron the appearance of copper, contrived by Mr Pomeroy of Cincinnati, who thus describes it—­rather laboriously, by the way:—­

’Immerse the iron in dilute sulphuric acid, for the purpose of cleansing the surface of the article which is to be coated; and thus cleansed, submit the iron to a brisk heat to dry it; when dry, immerse the article in a mixture of clay and water, and again dry it so as to leave a thin coating of the clay on its surface:  it is then to be immersed in a bath of melted copper, and the length of time requisite for the iron and copper to form a union, will depend on the thickness of the article under operation.  The object of the clay is to protect the copper from