The lecture given by Mr. J. D. Bishop at the Temperance Hall, on the 20th instant, was one calling for more than usual remark. Advertised as a "popular" lecture it did not belie its title, whilst, being at the same time essentially scientific in its treatment, the lecturer, we think, made an impression equally on those with whom science i pastime as well as on those with whom itis 8 study, The subject, "An hour with a battery," was one apparently of but little feneralintorost, because doubtless everyone OWS, 01 he "knows, all about it." We candidly confess we thought s0, too, and went prepared to listen to the usual class-book story about Galvani and his frogs, and Volta and his pile, enlivened with the ordinary experiments which are generally provided for in such catalogues as. those of Negretti, How, Jackson, Thorne-thwaite, Salomon, and scoresofothermakers, who advertise sets of apparatus which enable any intelligent amateur to give to an unintelligent audience a very passable experimental lecture. Nothing was said either of Volta or Galvani. We were agreeably disappointed, and from first to last the experiments were, to us at least, new and original in design and really perfect in practice. We have often read with wonder jow a chemist will take any substance, from face powder to benzenchexacarboxylic acid, and, bya series of processes, which remind one of the days of the inquisition, torture and rack it until it yields at last the grand secret of its every single constituent. Taking a small glass cell. containing about an ounce of sulphuric acid and water and small piece each of platinum and zinc, both not weighing more than 50 grains, the lecturer began by showing that the combination really did possess electro-motive power, by making it deflect a reflecting galranometer, the movements of which were rendered visible to the audience by the vibration of a circular spot of light xbout a foot in diameter, over a scale of proportionate magnitude. How it did this was made apparent by an apparatus which revealed on a screen six feet square every possible feature in the internal economy of this small glass cell. First it was exposed in a static state, or idle, then it was made to show itself hard at work, throwing off torrents of gas as & loconiotive does steam. Then the battery was set to work to decompose water and collect the oxygen. and hydrogen therefrom, each one in its respottive tubes, which, although but an inch oF #0 long, looked on the screen like Gigantic cucum ally taking leave Of their insides as the water left to make room for the gases. Then it had to show the audience how it could form beautiful crystals of solid metal from a solution of one of its salts, and again how it could return the solid metal back again to its original invisible state in the solution, Then it, was made to write in blue with a rod of iron, and without any in on Previously prepared paper in fact, it was ade to do everything which it could do, and do it well, too, After showing what 2 varied amount of work the chemical decomposition which took place in that call could. perform outside the cell, the lecturer shawed us how our commonest daily actions generated currents of eleckisty generally unsuspected yn. touch of the tongue on a gold locket, and sent the spot of light of His of sin the i of Bra emt po, the force of the correst touch of a wet finger did the asin: concluding experiment ons of the' galvanometer witee was fastened to a emall pewter mug and the other being held in the hand, Tan awful warning to beer drinkers, was Jaced by the lecturer's drinking some beer yen" by the current of electricity pro-
from the mug, which current was so power-fol as to song the spot of light with an indignant bound from Zero to nowhere, for it flow off and did not return, being cither indignant at thus being made sport of in the Temperance Hall or delighted beyond bounds at the strength of the lecturer's draught, Thus ended what was decidedly the best experimental lecture ever given in Shanghai. The audience was put inacomfortable humor by the quaint but earnest manner in which he lecturer addressed them, and continued rounds of applause greeted the successful! termination of each experiment. As a scientific lecture it was decidedly well studied and properly arranged, and even to those who had no taste for science pure and simple the experiments could not be otherwise than interesting as well as beautiful.
The evening being that prior to mail night, and the one on which the French mail happened to arrive just at the lecture hour, no doubt deprived many of the opportunity of going; but ever making this allowance it is not greatly to the credit of Shanghai that the hail was not more than half filled, to listen to and see the explanations of a thoroughly competent master of one of the most interesting and important branches of physical science.
On the termination of the lecture, W, B. Chalmers, Esq. proposed and T. W. Kingsmill, Esq., seconded a vote of thanks to the lecturer, which was carried as it deserved to be.
Text read from the printed page and cleaned; old type leaves the occasional error.