3 5 1 Royal Society of London. 



of that substance, according to the analysis of iliis inge- 

 nious chemist, there were (as near as we can recollect) 

 '22V grains of water and oil ; of ciiipyrcumatic oil about 30; 

 carbon 30 ; lime 9 ; carbonated hydrogen gas about 8. In 

 a postscript the author noticed a solution of guaiacum that 

 liad assumed the appearance of caout-chouc, t)ut when re- 

 duced to the solid form it became brittle. Of the chemical 

 accuracy of Mr. Brande's experiments there cannot be the 

 least doubt ; but he has for the present rested content with 

 o-iving only a general analysis, without entering into a de- 

 tail of all the constituent principles of this vegetable pro- 

 duct, to which he has very properly given the generic de- 

 nomination of extracto-resin. From these experiments, 

 and the more profound researches of the very accurate and 

 indefatigable Mr. Hatchelt, we may shortly expect to pos- 

 sess ample knowledge of the nature and properties of gums, , 

 resins, and balsams. 



On the same evening commenced the reading of a letter 

 from F. A. Knight, esq. to the right honourable Sir Joseph 

 Banks, on the descent of ,the roots, and the elongation of 

 the germs, of plants. To the right honourable President who 

 directs, and the philosopher who executes these vegetable 

 physiological researches, the public is deeply indebted ; and 

 Mr. Knight, perhaps with the exception of Hedwig, is al- 

 most the only botanist in Europe who seems to be convinced 

 tb.at botany is not a science but as it is connected with the 

 physiology of vegetation, and the anatomy of vegetables. 

 While other botanists are occupied with fruitless and dis- 

 gusting logomachies on terminology, this naturalist mo- 

 destly develops the progress of vegetation, the true philo- 

 sophy of botany, with an ardour, originality, and accuracy 

 of oliservation, that must eventually produce the most be- 

 neficial consequences to society. We would not deprive 

 Mr. Knight of the honour of presenting the public with 

 the result, of his researches in his own terms, by antici- 

 pating the consequent advantages to agriculture in deve- 

 loping the best means of administering the most proper 

 quantity and qualilv of food necessary to facilitate the 

 growth and augment the size of those plants which are in- 

 dispensable to animal existence. 



January 16, the right honourable the President in the 

 chair. ' Continuation of Mr. Knight's excellent paper on 

 vegetable radiation and germination. To determine whe- 

 ther the descent of the roots of plants was the efleet of an 

 inherent principle, or the consequence of mechanical gra- 

 vila-tion, the author placed diftcrcnt seeds in boxes attached 



to 



