536 PHILOSOPHICAL TRANSACTIONS. [anNO I67O. 



They often fasten their threads in several places to the things they creep 

 over : The manner is, by beating their tails against them as they creep along ; 

 which may be understood by the line, fig. 8, pi. 13. By this frequent beating 

 in of their thread among the asperities of the place, where they creep, they 

 either secure it against the wind, that it be not easily blown away; or else 

 while they hang by it, if one stick breaks another holds fast ; so that they do 

 not fall to the ground. 



An Account of some Boohs. N° 65, p. 2105. 



I. De Corporum AfFectionibus cum Manifestis turn Occultis, Libri Duo : seu 

 Promota6 per Experimenta Philosophiae Specimen. Auth. J. B. Du Hamel,* 

 Ecclesiae Bajocensis Cancellario. Parisiis, 1670, in l2mo. 



The learned author of this treatise having represented in the preface that the 

 Grecian philosophy concerning nature has been so far from being able to in- 

 crease, that it is rather esteemed to have degenerated and decayed ; gives here a 

 specimen of natural philosophy improved and advanced by observations and ex- 

 periments; not only endeavouring to explain, from the principles of modern 

 philosophers, the qualities and powers of bodies, but also giving an account of 

 the more notable experiments made in this age in divers places, as England, 

 France, Italy, Germany, &c. In the performance of which he treats. 



In his first book, of the origin and nature of qualities in general ; then of 

 heat and cold; of fluidity and firmness, and other tactile qualities; of tastes, 

 smells, sounds, light, and colour. In the second, of medicaments in general; 

 then of the virtue and use of preparing alterative, purgative, and topical medi- 

 cines; as also of poisons and antidotes. In the same, he proceeds to consider 

 magnetism, electricity, gravity in general, and the accelerated motion of heavy 

 bodies: concluding the whole with the consideration of librated liquors, and the 

 weight of the air. 



II. Elementa Physica, sive Nova Philosophiae Principia; ubi Cartesianorum 



* John Baptista du Hamel, a French philosopher, was born at Vire, in Lower Normandy, in 

 1624, and studied at tlie universities of Caen and Paris. At the age of Ip he printed an explanation 

 of Theodosius's Spherics, to which he added a neat Tract on Trigonometry. He entered among tlie 

 fathers of the oratory, but after eight years left them for a curacy. This he also resigned after three 

 years. He was the first secretary to the Royal Academy, being chosen in 1666 to tliat office, which 

 he held till 1697, when at his own request he was succeeded by M. de Fontenelle. He travelled in 

 England and several other countries, cultivating every where the acquaintance of the most eminent 

 philosophers. Du Hamel died at Paris, by the gentle and gradual decays of old age, in 1706, in the 

 83d year ot his age. He was author of a great many works on a variety of subjects, as mathematics, 

 philosophy, (among which should be mentioned his Regiae Scientiar. Academiae Histor.) metaphysics, 

 divinity, &c.j and was celebrated for his readiness and accuracy in tlie use of the Latin language. 



