72 



The author purposes communicating in a future paper his 

 researches on the other organs supplied by the vagus. 



The above experiments were principally carried out in the labora- 

 tory of M. Flourens at the Jardin des Plants, who facilitated in 

 every way the researches, and where the author had the able 

 assistance of Drs. Philipeaux and Vulpian. 



II. "Extract of a Letter to GEORGE RENNIE, Esq., F.R.S., 

 from P. A. SECCHI, Director of the Astronomical Obser- 

 vatory of the Collegio Romano, containing explanatory 

 remarks on a drawing of the Lunar Spotj 'Copernicus/ 

 presented by him to the Royal Society. Dated Rome, 

 March 13, 1856." Communicated by GEORGE RENNIE, 

 Esq., F.R.S. 



" As to the drawing of the spot of the moon, it is a first attempt 

 to obtain an accurate representation of the interesting spot ' Coper- 

 nicus.' In such large dimensions, photography directly taken 

 with the telescope has been impossible ; I therefore made first an 

 accurate triangulation of the spot with the micrometer, and the 

 principal points were thus laid down on the chart, after which opera- 

 tion the rest was filled in by the eye alone. The power used has 

 been always either 1000 or 760. As it was impossible to carry 

 through such a work in a single night, on the first night of good 

 opportunity a general outline was taken, and on the other evenings 

 particular drawings were made, and all these parts, taken in different 

 grades of light and shadow, were afterwards harmonized together and 

 compared with the moon when the point of light was seen to be the 

 same as on the first night. So this work occupied more than six 

 months, that is, all the favourable positions (two at each lunation) 

 which could be obtained. I do not pretend it to be yet accurate 

 enough to be transferred from photography* to any kind of en- 

 graving, but I am watching every good occasion to make it complete. 

 But before bestowing more time and labour, I should be glad to 

 know the impression such a work may make among the scientific 

 men of England. I must observe that the most distant outliers of 

 the crater have not been included," &c. 



* The figure presented to the Society is a photographic copy of the original 

 drawing. (D.) 



