42 Analyses of Boohs. [Jan. 



The author of this memoir is of opinion that an examination of 

 the action of vegetable substances on each other and of the 

 effects produced upon them by the action of air and water, is 

 the best method of investigating various effects of vegetation ; or 

 at least if it does not answer that purpose, it will lead to important 

 experiments respecting the theory of fermentation. Starch had 

 scarcely been examined under this point of view, or only indi- 

 rectly, and in a way quite insufficient to enable us to deduce the 

 requisite consequences. It had been observed that the seeds of 

 corn formed sugar during germination, and that this does not 

 happen ixnless they be impregnated with water, and air have 

 access to them. Hence it was concluded that the oxygen gas 

 which disappeared, producing carbonic acid gas, was the princi- 

 pal agent in the conversion of the starch into sugar. Vogel had 

 exposed a mixture of starch and sugar to the action of a boihng^ 

 heat for four days. The mixture became very fluid. It was 

 filtered. The filtered liquid being evaporated left a bitter muci- 

 lage, which had not the least of a saccharine taste. A horny 

 looking matter remained on the filter. Kirchoff" has discovered 

 that if one part of dry pulverized gluten be mixed with two parts 

 of starch made into a paste with water, and the mixture be 

 digested for 10 or 12 hours at the temperature from 122° to 167°, 

 the starch is partly converted into su^ar. Hence he has con- 

 cluded that the conversion of starch into sugar takes place during 

 germination. 



Such was the state of our knowledge before the experiments 

 which Saussure relates in the present paper. He mixed together 

 20 grammes of the best wheat starch, and 12 times the weight 

 of water, so as to form a thin paste. This was put into a large 

 flat cylinder forming a layer to the depth of two centimetres 

 (0-8 inch nearly). It was covered by a large receiver, below 

 which the atmospherical air had easy access, and left at rest for 

 two years in a place in which the temperature rose as high occa- 

 sionally as 724°. At the end of this period, it was a grey- 

 coloured liquid paste, covered with mucors, and almost without 

 smell. It produced no change on vegetable blues, and could no 

 longer be employed to paste substances together. After being 

 dried in the temperature of the atmosphere, its weight was con- 

 siderably diminished. If we suppose its original weight to have 

 been 100, it was reduced to 76-2 dried at the temperature of the 

 atmosphere, or to 80-46", supposing both dried at the tempera- 

 ture of boiling water. This residual matter was carefully 

 analyzed, and found to consist of the following substances : 



Sugar, 



Gum, 



Amidin, 



Starchy lignin, 



Lignin mixed with charcoal, 



Starch undecomposed. 



