18S On Numerical Proportions 



some resemblance in animal life ? In the cypress it is beautiful 

 to trace the different powders dividing and holding their course ; 

 the pollen to the male flower, the balls to the female. But still 

 more astonishing is it, when, as in the gooselerry and currant, 

 they are all pressed together, and yet never mistake their desti- 

 nation. In many plants, however, the pollen has a sort of funnel 

 placed in the pith, through which the powder proceeds to its 

 proper situation; but this is only just at the bottom of a col- 

 lection of buds, and it soon disappears with the increasing growth 

 of the plant. 



As this short letter was only written to mention the time of 

 the rising of the seeds, and to enable each botanist to judge of 

 the discovery, I shall here conclude, hoping that I have obviated 

 all the objections that can be made to its validity. 

 1 am, sir. 



Your obliged humble servant, 



Agnes Ibbetson. 



P. S. — I have troubled the reader with only two prints just to 

 show the specimen of Malpighi, fig. 1 . which is perfectly just 

 (only be did not look at the proper time, and did not therefore 

 see the seeds), and the seed-vessel of the arum, with the seeds 

 mounting to the flower and entering the various seed-vessels : 

 see fig. 2. The seeds running into the seed-vessels of the larch, 

 I have already given in volume xxxv. page 1, of Nicholson's 

 Journal. 



I forgot to mention that in most fruits, pears, apples, walnuts, 

 &c. the embryo of the seed is of a greenish colour. 



XXXIV. Letter from M. Ampere to Count Berthollet, on the 



Delerminat'ion of the Proportions in which Bodies combine, 

 according to the Number and respective Arrangement of 

 the Molecules of which their integrant Particles are com- 

 posed. 



[Continued from p. 116.] 



W E have seen that eight tetrahedrons may be united in a re- 

 presentative form, which has been designated under the name of 

 cubo-hexa-tetrahedron. In this arrangement, the position of 

 two tetrahedrons differs from that of the six others ; but it is easy 

 to unite the same number of tetrahedrons, by giving to all of 

 them the same respective position. For this purpose we shall 

 conceive that one of the summits of each tetrahedron is placed 

 at one of the eight solid angles of a cube, and that this tetrahe- 

 dron is situated in such a way that its three other summits are 



in 



