518 



SbeU lime. 

 Kitre beds, 



Nature of lu- 

 minous me- 

 teors. 



Meta!s from 

 thtt alkalis. 



An omma ab 



Chemical ex* 

 planatioas of 



«l(ic{.ficity. 



SCIEKTinc NEWS. 



11. What is the chemical reason why stone lime makes 

 OQ the whole more firm and durable buildings than shell 

 lime, and how may the latter be improved in this respect? 



X'i. May nitre beds be profitably formed in this country, 

 particularly in places where the water is impregnated with 

 fceveral substances produced by the putrefaction of animal 

 matters? and what rules should be observed respecting ,j, 

 them? I 



13. What do we know, from incontestible observations, 1 

 of the nature of luminous meteors, or those that have the | 

 appearance of fire, lightning excepted, which occasionally 

 appear in our atmosphere? how far can they be explained 

 by known experiments? and how much is there still gra- 

 tuitous or doubtful in what the philosophers of the present 

 day h«ve asserted respecting them ? 



14. C'in it be demonstrated by incontrovertible experi- 

 ments, that ti^e substances which have the appearance of 

 metals, produced from alkaline salts, are real metals ? or 

 are there sufficient reasons to maintain, that they are hy- 

 dr.irets, p oduced by the combination of hidrogen with the 

 alkalis? What is the most certain and convenient mode of 

 producing these substances from the alkaline salts in pretty 

 considerable quantity by means of a high tenipfrature ? 



14. Mow fiir may We still maintain the doctrine of Harvey, 

 that animals are born in general from preexisting eggs, and 

 that plants spring only from seeds ? and on the contrary 

 what are the principal observations that show, that there 

 are animals and plants, which are produced in a different 

 mode ? 



l6. What judgment is to be formed of the chemical 

 explanations attempted to be given of electrical phenomena ? 

 Are there any founded on sufficient experiments, or that 

 may be proved by new ones ? Or are tliey to be considered 

 bitherto as hypotheses by no means proved, or advanced 

 without valid reasons? 



The time for answering all these questions is previous to 

 the 1st of January, 1812. Beside the usual medal, value 

 Voduc, [£13 : 17 : 6], 30 ducats in addition will be given 

 ' to those who answer questions 2, 3, 4, 7* 10, 11, 13, 14, 

 and 15 ; and 50 due. [£23 : 2 : 6] in addition to questions 

 I uod 5. Academical 



