SCIENTIFIC NEWS. ^\J 



Imperial Academy at Petersburg. 



The following prize subject is proposed by this academy Imperial Ras- 

 for the year 1810. siai1 A ""le,nv . 



" To improve the theory of sluices, and thence to deduce Prize question 

 rules for constructing these important works in the most ad- for 18l0 » 

 vantageous manner; so that they may be used with all pos- 

 sible security and speed, be attended with as little expense 

 as may be for their construction and keeping in repair, and 

 incur no waste of the water required for the passage of load- 

 ed vessels more than is absolutely necessary." 



And for 1811. " To give a complete comparative chro- and for lMi. 

 nology, and, if possible, corrected and verified, of the Bv- 

 zantine authors, from the foundation of the city of Constan- 

 tinople till its conquest by the Turks." 



The prize for each is 100 Holland ducats [£46 5s.], and 

 the answers must be sent before the 1st of July in each 

 year. 



Mr. Peter Alomani, of Milan, has analysed a new sne- Analysis of a 

 cies of urinary calculus. In 100 parts he found pure mag- ur »!>ary stone. 

 nesia 51, silex"20, phosphate of iron 11-34, carbonate of 

 magnesia 4. The volatile substances and loss amounted to 

 3'1 6. [One of these numbers has evidently a deficiency 

 of 10.] 



- Dr. G. Melandri, of the same place, is examining the Artificial t ar . 

 artificial tannin of Mr. Hatchet, but in another point of nin. 

 view. His researches are on the tannin of different plants 

 and vegetable products. He thinks, that it is not an oxide 

 of carbon: but an oxide with a binary, or more probably 

 ternary radical. The nitrogen of the nitric acid must enter 

 into its composition ; as must the nitrogen of the animal 

 charcoal, since this succeeds better than vegetable charcoal. 

 He believes too, that hidrogen enters into it, though in 

 -mall quantity. 



On analysing deadly nightshade, atropa lellatknva, he Analysis of 

 discovered in the leaves a salt never before observed in v^-Ufeadly 

 gelables, the oxalate of magnesia, joined with free oxalic * 

 acid. The other substances in them were oxalate of lime, 



niuiiafe 



