iv CONTENTS. 



APRIL, 1 805. 



Engravings of the following Objects : 1. A Quarto Ptate, exhibiting magnified 

 Repr.efentatiorts of the destructive parafitic Plant which caufes the Blight in 

 Corn, -md its Situation and Growth in the Pores or Mouths of Wheat Straw; 

 2. Another Q^ai to Plate, (hewing, by highly magnified Sections and Views, the 

 Structure of Wheat Straw, and the Plant itfelf as it vegetates in the cellular 

 Texture beneath the Bark. Tliel'e two Plates are from Drawings of the lame 

 fue, by M.Bauer, Botanical Painter to the King j 3. Mathematical Diagrams 

 of fome Properties of the Triangle, by Mr. Gough ; of the Circle, by a 

 Correfpondent ; and of an Application of Spectacle Glades, by Mr. Ezekiel 

 Walker. 



I. A mort Account of the Caufe of the Difeafe in Corn, called by Farmers, 

 the Blight, the Mildew and the Ruft. Reprinted, and the Plates copied, with 

 Permifilon, from a Memoir communicated by the Right Hon. Sir Joseph. . 

 Banks, Bart. P. R S. &c. &c. &c. With fome additional Notes. P. 225 



II. Theorems reflecting the Properties of the Sides of Triangles interfered 

 by Right Lines drawn from the three Angles fo as to meet in one Point. 

 By Mr. John Gough. ------ 234 



III. A Communication on the Ule of Green Vitriol, or Sulphate of Iron, as 

 a Manure; and on the Efficacy of paring and burning depending, part- 

 ly, on Oxide of Iron. By George Pearfon, M. D. Honorary Member 

 of the Board of Agriculture, F. R. S. • From a Communication made by him 

 to the Board, and ini'erted in the 4th Vol. of their Trnnfactions. 239 



IV. On Spectacles. In a Letten from Mr. Ezekiel Walker. - 243 



V. Remarks on certain PafTages in Dr. Thonifon's Chemiftry, together with 

 fome Experiments on Sandarach and Maltic, In a Letter from Mr. R. 

 Matthews. - - - - - 2<15 



VI. The Dutch Method of curing Herrings, extracted and tranflated from the 

 German of Kriinitz's Economical Encyclopaedia (Oeconomifche Encyclopadie) y 

 Article Hiking, by J. Hinckley, Efq. F. S. A. - - - 248 



VII. The Denfity of Mercury in its folid State afcertained. By Mr. John 

 Biddle. - - - - ' - - 253 



VIII. Obfervations on Mr. BofwelPs Geometrical Propofitions. By An Old 

 Correfpondent. - - - - - - 253 



IX. A Memoir on Milk and the Lactic Acid. By Cit. Bouillon Lagrange. 257 



X. An Analyfis cf the Magnetical Pyrites ; with Remarks on fome of the other' 

 Sulphurets of Iron. By "Charles Hatchttt, Efq. F. R. S. From the Phil. 

 Tranf. for 1804. - - - ' . - " 265 



Xf. Anfwer to a Letter of C. L. with other Remarks, on the Images formed 

 by convex Lenfes. In a Letter from Mr. Ezekiel Walker. - 27b' 



XII. Account of an Aeroliatic Voyage, made by M- Gay-Luflac on the 29th 

 Fru&idor, in the Vt.it 12. Read to the National Inftitute on the 9th Ven- 

 demiaire, in the Year 13. - - - - - 278 



XIII. Experiments and Obfervations on the Motion of the Sap in Trees. In a 

 Letter from Thomas Andrew Knight, Efq. to the Right Hon. Sir Jofeph: 

 Banks, Bart. K. B. P. R. S. From the Phil. Tranf. for 1804. 289 



XIV. Extract of a Memoir of Mr. Erman, entitled, Obfervations and 

 Doubts concerning Atmoiphenc Electricity. - 2^4 



Scientific News. - - - - .. . _ 30 1 



Extract of a Letter from Mr. J. DaJton, Lecturer at the Royal Inftitution. 303 

 To Correfpondent?. ---_„- 304, 



