VOL. XXXVI.] PHILOSOPHICAL TRANSACTIONS. 359 



Sir Hans Sloane deserves a much less degree of praise for having detected this 

 false kind, which was insensibly creeping into use, the effects of which might 

 otherwise have proved as fatal as the other is found to be beneficial. 



This poisonous kind of apocynum is now cultivated by several curious persons 

 about London. 



j4n Account of a Book entitled, Hesperi et Phosphori Nova Phtenomena, &c. 

 Auctore Francisco Bianchino. By John Hadley, Esq. R. S. V. Prces. 

 N°410, p. 158. 



The design of this treatise, is to give an account of some new astronomical 

 discoveries relating to the planet Venus, which the author disposes under four 

 heads ; viz. 



1. The description of the dusky spots observed in her disk. 1. Her rotation 

 round an axis, the position of which is determined by the apparent motion of 

 those spots, with the time of her revolution. 3. The parallelism of that axis 

 to itself in all parts of the planet's orbit. 4. Observations in order to deter- 

 mine the horizontal parallax of Venus, and consequently those of the sun and 

 other planets. 



He takes notice of 5 remarkable spots in her whole surface; the two smallest 

 of which are placed, one near each pole, the other 3 lie along the equator, and 

 cover good part of a zone, extended to about 30 deg. of latitude on each side. 

 He represents them to be much like the larger dark spots in the moon, which 

 are usually called seas, but considerably fainter, so as not to be easily discernible, 

 even to a sharp-sighted observer, without the assistance of a telescope, capable 

 of representing distinctly the planet under an angle equal at least to that under 

 which the moon appears to the naked eye, and with an aperture of 3 or 4 

 inches of the Roman palm. 



This revolution he makes greatly different from those of the earth and Mars, 

 both in the position of the axis and time of the period. He places the colurus 

 solstitiorum, or plane passing through the axis of the planet and tropical 

 points of its orbit, about the 20th degree of Leo and Aquarius, and gives the 

 planes of its equator and ecliptic an inclination to each other of about 75 de- 

 grees. He determines the time of the revolution to be about 24 days and 8 

 hours, instead of 23 hours, as it has been generally taken to be from some ob- 

 servations made by Mr. Cassini in the years l666 and J 667, but which he him- 

 self did not seem much to rely on. 



The next article of his observations is the continuance of the axis in the 



