402 Miscellanies. 



by ihe professors whose duty it is to visit their shops, are found to be 

 nothing more than preparations described in the formularies of Paris, 

 London, Edinburgh, Vienna, Berlin, &;c. which they have thus ap- 

 propriated to themselves and sell under names of their own invention. 

 Such deception, which has all the characters of fraud, produces se- 

 rious inconvenience, and must be attended with unhappy consequen- 

 ces. To suppress it, one of the most effectual means would be, to 

 order that all simple or compound substances, used either in the arts 

 or medicine, should be sold only under the name, or one of the 

 names, by which they are generally known, so that the purchasers, 

 by consulting the works which treat of these substances, may always 

 ascertain their nature, quality and use. The counterfeiters, brought 

 before the proper tribunals, would then become subject to the penal- 

 ties against fraud. — Ide77i, 



46. Chemico-JWagnetisrn. — M. Zantedeschi, of Pavia, in a com- 

 munication to the Bib. Univ. of Geneva, states, that he had perceived 

 a more decided chemical action in needles suspended from a horse- 

 shoe magnet, than in those unconnected with magnetism, and also a 

 stronger action at the north pole than at the south. His experiments 

 are in direct opposition to those of Professor Erdmann, and there- 

 fore need confirmation. But he further states, that having taken a 

 horse-shoe magnet, of about one pound in weight, and capable of 

 supporting from four to five pounds, he bound a very fine copper wire 

 round each of its poles, each wire extending fifteen or sixteen feet 

 beyond the magnet. In connecting the ends of these wires with 

 those of a multiplier of two needles, he observed a deviation of 8° to 

 10° sometimes in one direction and sometimes in the other, accord- 

 ing to the position of the poles of the magnet. This phenomenon, he 

 observes, could not be attributed to the electromotive faculty of the 

 metals. Since each side was symmetrical, and precautions were ta- 

 ken to prevent any effect from temperature. It appears, therefore, 

 that the north pole of a magnet acts like the zinc pole of a voltaic 

 battery. Prof. Z. wishes that other experimenters may repeat the 

 trial with more sensitive instruments. — Bib. Univ. Jan. 1830. 



47. Analyses of Pollen, by Macaire-Prinsep. — The only dust 

 of the stamina of plants which has been subjected to analysis, is that 

 of the date tree [Phcenix dactylifera) brought from Egypt by Delille. 

 Fourcroy and Vauquelin found it disagreeable to the taste, and they 



