ri CONTENTS. 



JULY, 1812. 



.Engravings of the following Subjects: 1. Dissections of a Flower, in a 4t© 

 Plate: and 2. A Branch of Laburnum, with a Section considerably magni- 

 fied; all delineated from Nature by Mrs. Agnes Ibbetson. 



I. On the Dissection of Flowers. In a Letter from Mrs. Agnes Ibbetson 165* 



II. Remarks on the Perforations made in Paper by Electrical Batteries. In a 

 Letter from Mr. John Gough - 176 



III. On some Preparations of Gold lately employed medicinally. By A. S. 

 Duportal, M. D., &c, and Th. Pelletier, Apothecary - 179 



IV. Experiments on the Existence of Water in Muriate of Ammonia formed 

 by the Combination of Muriatic Acid and Ammoniacal Gasses. By Mr. 

 John Murray, Lecturer on Chemistry, Edinburgh - - 183 



V. Meteorological Journal, by Luke Howard, Esq. - 198 



VI. Account of the Pitch Lake of the Island of Trinidad. By Nicholas Nu- 

 gent, M. D., Hon. Mem. of the Geol. Soc - - 200 



VII. Chemical Experiments on Indigo. By M. Chevreul - 211 



VIII. On the Action of Muriatic Acid on Sugar, and the Nature of its Prin- 

 ciples. In a Letter from John Nowell, Esq. - - 216 



IX. On the Zig-zag Motion of the Electric Spark. In a Letter from J. A. De 

 Luc, Esq. F. R. S. - - - - 226 



X. Remarks on an Artificial Stony Substance. By F. R. Curaudau 230 

 Scientific News. . - • - - - 232 



AUGUST, 



