Produced by Juliet Sutherland and the PG Online Distributed Proofreading Team at www.pgdp.net. [Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 829 NEW YORK, November 21, 1891. Scientific American Supplement. Vol. XXXII, No. 829. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS. I. ASTRONOMY.--The Sun's Motion in Space.--By A.M. CLERKE.-- A very interesting article on the determination of this hitherto uncertain factor. II. BOTANY.--Hemlock and Parsley.--By W.W. BAILEY.--Economic botany of Umbelliferae. Raphides--the Cause of the Acridity of Certain Plants.--By R.A. WEBER.--Effect of these crystals on the expressed juice from calla and Indian turnip and other plants. The Eremuri.--A very attractive flower plant for gardens.--1 illustration. III. DECORATIVE ART.--The Decorative Treatment of Natural Foliage.--By HUGH STANNUS. The first of a series of lectures before the London Society of Arts, giving an elaborate classification of the principles of the subject.--5 illustrations. IV. ELECTRICITY.--The Independent--Storage or Primary Battery--System of Electric Motive Power.--By KNIGHT NEFTEL.--Abstract of a recent paper read before the American Street Railway Association on the present aspect of battery car traction. V. GEOGRAPHY.--The Colorado Desert Lake.--A description of the new overflow into the Colorado Desert, with the prognosis of its future. VI. GEOLOGY.--Animal Origin of Petroleum and Paraffine.--A plea for the animal origin of geological hydrocarbons based on chemical and geological reasons. The Origin of Petroleum.--By O.C.D. Ross.--A further and more lengthy discussion in regard to petroleum and theory of its production by volcanic action. VII. GUNNERY.--Weldon's Range Finder.--An instrument for determining distances, with description of its use.--3 illustrations. VIII. MECHANICAL ENGINEERING.--Mercury Weighing Machine.--A type of weighing machine depending on the displacement of mercury.--1 illustration. Wheels Linked with a Bell Crank.--Curious examples of mechanical constructions in the communication of motion between wheels.--3 illustrations. IX. MEDICINE AND HYGIENE.--Cold and Mortality.--By Dr. B.W. RICHARDSON.--The effect of cold upon the operation of the animal system, with practical rules. On the Occurrence of Tin in Canned Food.--By H.A. WEBER.--A very valuable and important series of analyses of American and other food products for tin and copper. The Treatment of Glaucoma.--Note on the treatment of this disease fatal to vision.