148 PHILOSOPHICAL TRANSACTIONS. [aNNO I667. 



II. Astronomia Reformata, Auctore Johanne Bapt. Riccioli,* Soc. Jesu. 

 The design of Riccioli in this work, is to examine the different hypotheses of 



several astronomers, as to the system of the world ; in which he finds great 

 difficulty to conclude any thing certain. He expected to reform what he 

 esteemed the errors which some astronomers had fallen into ; but unfortunately 

 takes a wrong direction, and becomes a strenuous advocate for the immobility 

 of the earth. 



III. Anatome Medullas Spinalis, et Nervorum inde proventium, Gerardi 

 Blasii, M. D. The Anatomy of the Spinal Marrow, and of the Nerves that 

 arise therefrom. By Dr. Gerard Blasius.-f- 



The author shows in this little tract a way of taking the entire medulla 

 spinalis or marrow of the back out of its theca or boney receptacle, without 

 laceration, which else happens frequently both to the nerves proceeding 

 from it and to the coats investing it ; not to name other parts of the same. 

 This he affirms to have been put in practice by himself, by a fine saw and 

 wedge; which are to be dexterously used: and he produces accordingly in ex- 

 cellent cuts the representations of the structure of the said medulla thus taken 

 out, and the nerves thence proceeding; and that of several animals, dogs, 

 swine, sheep. 



He intermixes several observations, touching the singleness of this medulla 

 against Lindanus and others; its original, viz. Whether it be the root of the 

 brain, or the brain the root of it : its diff^erence of softness and hardness in se- 

 veral animals ; where he notes, that in swine it is much softer than in dogs, &c. 



former of these being the most useful and truly scientific of the whole^ His taste in the mathema- 

 tics was genuine and correct^ making considerable improvements in algebra, geometry, dioptrics, 

 and in mechanics. But in philosophy he failed, his genius taking a wrong turn through tlie brilliancy 

 of his imagination, which led him to invent systems of nature, instead of investigating her laws by 

 means of judicious experiments^ painfully and patiently pursued. 



Descartes's chief work in pure mathematics, was his application of algebra to the geometry of 

 curve lines ; making those two sciences mutually subservient to each other, to the improvement of both. 



He conducted, during the greatest part of his life, considerable, not to say violent controversies 

 with his contemporary philosophers ; most of which are extant in the several volumes of letters which 

 have been published with the collections of his works. 



* John Baptist Riccioli, a learned Jesuit, was bom at Ferrara in 1598, and died in 1671, at 73 

 years of age. He was author of several considerable works, as, 1 . Almagestum Novum ; in which, 

 after the manner of Ptolemy, he collected every thing relating to astronomy, ancient and modern, 

 2. Astronomia Reformata, above-mentioned. 3. Chronologia Reformata. Riccioli took great 

 pains in collecting information, and employing it to the best purpose. But it would seem that the 

 prejudices of his order had induced him to adopt an erroneous hypothesis as to the system of the world. 



■f Gerard Blasius was professor of physic at Amsterdam in the latter part of the 17th century. 

 He was author of several Latin tracts on medical, chemical and anatomical subjects j among the most 

 celebrated of which may be numbered his Anatome Animalium, 



