266 M. Wartmann's First Memoir 



Supposed existence of Mannite in the Roots o/'Triticum repens, 

 or Couch-grass. 



In a note on the article Mannite, in the eighth volume of the 

 last German edition of Berzelius's Lehrbuch^ it is stated that 

 Professor PfafF had succeeded in obtaining mannite from the 

 roots of Triticum repens^ or couch-grass. M. PfafF says that 

 he treated the extract of the couch-grass roots with boiling 

 alcohol, which on cooling deposited a number of long needle- 

 shaped crystals, which he believed to be a new species of 

 sugar, but which Berzelius is rather disposed to regard as 

 more probably mannite. I have twice repeated M. PfaflTs 

 experiment on two different quantities of couch-grass roots, 

 but with very opposite results. The alcoholic solution on 

 standing deposited it is true a quantity of long slender cry- 

 stalline needles. These, however, had not a sweet taste, and 

 when thrown into hot sulphuric acid they dissolved with effer- 

 vescence without blackening the solution. When heated on 

 platinum foil they melted, and left a white fusible alkaline 

 residue, which, when neutralized with muriatic acid, produced 

 a yellow crystalline precipitate in an alcoholic solution of pla- 

 tinum. I have every reason to believe, therefore, that these 

 acicular crystals were merely binoxalate of potash. The grass 

 roots certainly contained a great deal of an uncrystallizable 

 sugar which readily fermented. 



XLIV. First Memoir on various Phenomena of Induction. 

 By M. Elias Wartmann, Professor in the Academy of 

 Lausanne^. 



1. rriHE phaenomena of electric induction have been studied 

 ■I- for some years past by a great number of physicists. 

 Much however is still to be desired in the way of the determi- 

 nation of the laws which govern them and the establishment of 

 a theory which binds all these laws together. 



2. In this first memoir I propose to make known various 

 new results which I have obtained. I shall hereafter endea- 

 vour to show what is their relation to other electric phseno- 



* Translated from an article in the Archives de P Electricite, itself ex- 

 tracted from vol. X. No. 10 of the Bulletins de V Acad. Roy. de Bruxelles. 

 The principal results of these researches, and some of those which will be 

 found in the second memoir, the author states, were communicated to the 

 Society de Physique et d'Hist. Natur. de Geneve, at the meetings of the 

 7th of April and 6th of October 1842; as well as to the Societe des Sciences 

 Naturelles du Canton de Vaud {Bulletins, No. 3, pages 63, 65, 68; No. 5, 

 p. 112> 



