1 30 Linnaan Society. 



of this kind will, independently of their precision, have the advan- 

 tage of being identifiable at all times and in all countries ; the small- 

 ness of the apparatus is an additional recommendation, nothing 

 more being necessary than a little cupel, containing in separate cells 

 the requisite number of pyrometric alloys, each of the size of a pin's 

 head. The specimens melted in one experiment need only to be 

 flattened under the hammer in order to be again ready for use. For 

 the purpose of concisely registering the results, the author employs a 

 simple decimal method of notation, which at once expresses the na- 

 ture of the alloy, and its correspondence with the scale of temperature. 

 As the distance between the points of fusion of silver and of gold 

 is not considerable, the author divides this distance on the scale into 

 ten degrees ; obtaining measures of each by a successive addition 

 of 10 per cent of gold to the silver, the fusion of which, when pure, 

 marks the point of zero, while that of gold is reckoned at 10 degrees. 

 From the point of fusion of pure platina to that of pure gold, the au- 

 thor assumes 100 degrees, adding to the alloy which is to measure 

 each in succession, one per cent of platina. The author then enters 

 into a detailed account of the method he employed for ensuring accu- 

 racy in the formation of the requisite series of alloys, and of various 

 experiments undertaken to ascertain their fitness as measures of high 

 temperatures. The. remainder of the paper contains the recital of the 

 author's attempts to determine, by means of an apparatus connected 

 with an air-'tftermometer, the relation which the fusing point of pure 

 silver bears to the ordinary thermometric scale. 



A paper was likewise read, entitled, " On Alimentary Substances ; 

 by Sir George Smith Gibbes, M.D. F.R.S." 



After a few remarks on the very scanty assistance which physio- 

 logy and pathology have yet derive^ from the chemistry of orga- 

 nized substances, notwithstanding the great improvements which 

 have been lately introduced in the methods of analytical research, the 

 author maintains the proposition, that all alimentary substances, 

 whether belonging to the animal or vegetable kingdoms, retain some 

 principles originally the result of vitality, which they communicate to 

 other bodies, and thus constitute their food. He considers the ap- 

 pearances of the infusory animalcula, and more especially of the 

 Monas Termo, during the decomposition of alimentary substances as 

 favouring this hypothesis. In support of this argument, he adduces 

 experiments by Dr. Ingenhouz, himself, and others, from which he 

 infers that these animalcula perform some definite function during 

 the growth of vegetables. 



From the circumstance of chloride of lime preventing the deve- 

 lopment both of vegetation and of infusory animalcula, the author 

 infers that these animalcula are instrumental in the production and 

 growth of plants. 



LINNJEAN SOCIETY. 



Dec. 4. — Read a paper " On the Locomotive Power of the Snail, 

 by Mr. James Main." The author describes as the species which 

 have chiefly come under his notice the following ; — Limax maximus: 



ater : 



