Contents. v 



No. PAGE 



XXVII.— The Electrical Eesistance of Porcelain at Different Tempera- 

 tures. By B. G. Allen, b.sc. (lond.), a.r.c.sc.i. (June, 

 1918.) ... • '• • • .289 



XXVIII.— Observations on the Morphology of Larix leptolepis. By Joseph 



Doyle, b.a., m.sc. (Plates XVII-XVIII.) (August, 1918.) 310 

 XXIX.— The Insulating Properties of Erinoid. By E. G. Allen, b.sc. 



(lond.), a.b.c.sc.i. (August, 1918.) . ... 331 



XXX.— A Disease of Flax Seedlings caused by a species of Colletotrichum, 

 and transmitted by Infected Beed. By George H. Pethy- 

 bridge, b.sc, ph.d., and H. A. Lafferty, a.r.c.sc.i. (Plates 

 XIX-XX.) (August, 1918.) . • ■ -359 



XXXI.— The Determination of the Eate of Solution of Atmospheric 

 Nitrogen and Oxygen by Water. Parti. By W. E. Adeney, 

 d.sc, a.r.c.sc.i., f.i.c, and H. G. Becker, a.r.c.sc.i. (Plate 

 l XXI.) (August, 1918.) . . ■ ■ -385 



XXXII.— The Absorption of Water by Vulcanized Fibre and Erinoid on 

 Exposure to Moist Air, and the consequent Change of 

 Electrical Eesistance. By E. G. Allen, b.sc. (lond.), 

 a.r.c.sc.i. (October, 1918.) . . . .405 



XXXIII. —The Twist and Magnetization of a Steel Tube in a Spiral 

 Magnetic Field. By F. E. Hackett, m.a., ph.d. (October, 

 1918.) . ., ■ • • • -415 



XXXIV. — Mahogany, and the Becognition of some of the Different Kinds 

 by their Microscopic Characteristics. By Henry H. Dixon, 

 sc.d., f.r.s. (Plates XXII.- XLIV.) (December, 1918.) . 431 

 XXXV.— A Disease of Tomato and other Plants caused by a New Species 

 of Phytophthora. By George H. Pethybridge, b.sc, ph.d., 

 and H. A. Lafferty, a.r.c.sc.i. (Plates XLV.-XLVII.) 



(February, 1919). -487 



XXXVI.— Exudation of Water by Colocasia antiquorum. By Margaret 



G. Flood, b.a. (Plates XL.VIII.-XL.VIHa.) (April, 1919.) 506 

 XXXVII. — The Determination of the Volatile Fatty Acids by an Improved 

 Distillation Method. By Joseph Eeilly, m.a., d.sc, f.r.csci., 

 and Wilfred J. Hickinbottom. (Plate XLIX.) (April, 1919.) 513 

 XXXVIII.— Solar Halos seen at Greystones, Co. Wicklow, on September 

 22nd, 1879 ; and in Texas and Ohio, U.S.A., on October 

 3rd, 1917. By Sir John Moore, m.a., m.d., d.sc, f.r. met. soc 



(Plate L.) (April, 1919.) 539 



XXXIX.— Two New Species of Collembola from Nyassaland. By George 



H. Carpenter, d.sc, m.r.i.a. (Plate LI.) (April, 1919.) . 543 



b 



