CONTENTS. V 



11,12. Daily magnetic variation — Economical process for im- 



Page. 



itating silver paper, 



- 189 



13, 14, 15. Pressure of sand — Cement from iron filings — Con- 

 centration of sound, - - - - 190 

 16, 17. Dangerous plant among water-cresses — Thunder storms 



in France, 



191 



STATISTICS. 



- 192 



1. Mortality of infants, .... 



2, 3. Phthisis pulmonalis in Paris — Establishment of a model 



farm in Greece, - 



4. Science in Madrid, - 



5,6. Hygiene — English Universities, - - - 195 



- 193 



194 



ADDITIONAL EDITORIAL SELECTIONS. 



1. Dr. Mitchell's method of working caoutchouc, - - 195 



2. Strength of wine and other bottles, - - - 196 



3. Magnesium — Metal of magnesia, ... 197 



4. 5. Decrepitating common salt — Manufacture of bicarbonate 



of soda, • --... 



198 



6, 7. Russia diamond mines — Premature Explosions, - 199 



ADDITIONAL EXTRACTS, BY PROF. GRISCOM. 



1. Force of vapor at different temperatures, - - 201 



2, 3, 4. Safety of steam boilers — Translation of the Mecanique 



Celeste — Germination upon mercury, - - 202 



5, 6, 7. Boring for water — Preservation of iron from rust 



Beet sugar, 



203 



8, 9. Hydrophobia — Silicine — P. S. Bedford mineral springs, 204 



NUMBER II. 



Art. f. On the best method of obtaining and preserving Potas- 

 sium ; by L. D. Gale, M. D. Ass't to Prof. Chem. Coll. 

 Phys. and Surg. New York, - 205 



II. Instructions for collecting Insects for cabinets; by M. 



Theodore Roger. Translated from the French, by 

 Jacob Porter, M. D. 



III. On the Mineralogy and Geology of St. Lawrence County, 



213 



New York ; by J. Finch, F. B. S. &c. - - 220 



