184 Free Economical Society of Peterjhurgb, 



made in this refpect in the laft tables. In thefe calculations, 

 C. Lai ancle has kept in view the perturbations which Venus 

 experiences bv the action of Jupiter and that of the earth, 

 according to the formulae which he gave himfelf in the Me- 

 moirs of the Academy of Sciences. 



Natural Hi/lory. — C. Jurine has made fome curious ob- 

 fervations on the puce monocule, called commonly the water 

 flea (nio no cuius), a final I cruftaceous animal which abounds 

 in itagnant water, and which fometimes has given rife to 

 reports of fhowers of blood, becaufe the eggs, with which it 

 is full in the fpring-time, give it a red colour, fo that the 

 water where there are a great many of thefe infects, feems 

 really to be mixed with blood. 



The ableft natural i ft s, Swammerdam, De Geer, Scha?flFer, 

 and Otto Frederic Muller, have fucceflively ftudied this ani- 

 mal ; but Nature is inexhauflible even in her leail produc- 

 tions, and C. Jurine, of Geneva, aflbciate of the Inftitute, 

 has Mill difcovered, refpecting this infect, a number of curious 

 particulars which had efcaped thefe learned naturalifts. 



The molt lingular fact difcovered bv C. Jurine is, that a 

 female which has had intercourfe with the male, tranfmits the 

 influence of it to her female defendants ; fo that they all 

 lay eggs, without being obliged to couple, till the fixth gene- 

 ration ; after which their young periuS in moulting. An* 

 other fpecics carried this influence to the fifteenth genera- 

 tion. It is well known that Bonnet made fimilar observa- 

 tions in regard to pucerons. Thefe generations produced 

 without copulation are lefs abundant, and fucceed with lefs 

 rapidity, than thofe in which the males have had a fhare. 



THE FREE ECONOMICAL SOCIETY OF PETERSBURGH. 



In an extraordinary fitting of the Society on the 16th of 

 April, which was attended by a great number of the prin- 

 cipal members, there was read the following 



Letter from his Imperial Majejly: 



u All inftitutions eftablifhed for the benefit of my fubjects 

 ■fhall always be objects of my particular attention, and there- 

 fore the Free Economical Society may rely upon having my 

 fupport and protection. I confider their labours, both in re- 

 gard to their object and confluences, , as worthy of refpect ; 

 and, to promote their influence on the general good, I have 

 ordered the imperial' trtuiurer to pay to the Society yearly 

 the fum ot live thoufand roubles. In regard to changing 

 the pre fen t inipreffion of its medal, it is my opinion that 

 none can be litter for that purpofe, or more agreeable to 

 4 the 



