500 PHILOSOPHICAL TRANSACTIONS. [aNNO 1681. 



1. A way how a man may swim under water like a fish, as in fig. 6, pi. 14. He 

 breathes by the help of a bag about his head, containing a quantity of air, which 

 also keeps his head buoyant : through this he sees before him by the help of a 

 flat glass, fixed in it just before his face. He moves himself by ducksfoot pat- 

 tens, applied to the soles of his feet. He buoys up, or sinks himself in the 

 water, by the help of a vacuum pump, wherein, by the help of a rack and winch 

 to be turned with his hand, he can with ease make a greater or less vacuity, and 

 consequently make himself lighter or heavier in the water, &c. — 2. Another way 

 of swimming under water, and breathing by the help of a leathern pipe, kept 

 open by spiral wires, and extending from the swimmer's head to the top of the 

 water; a description of which you have in fig. 7. — 3. A way to make a sub- 

 marine vessel, by which several persons may pass together from place to place 

 under water, accommodated with ways to row and move it to and fro, and to 

 make it rise and sink in the water, &c. It is supposed it may be much like that 

 which Mersenne long since published from the shape and make of it, fig. 8.—- 

 4. A net-like form of the carnous fibres of a muscle; by which he supposes the 

 contraction or shortening of those fibres to be made, as may be conceived from 

 fig. 1, pi. 15, where by pulling the muscles abroad sidewise, they are contracted 

 lengthwise. 



Phocipna ; or, The Anatomy of a Porpm, dissected at Greskam College ; with a 

 preliminary Discourse concerning Anatomy, and a Natural History of Animals; 

 by Edward Tyson, M. D. Lond. Philos. Collect. N° 2, p. 37. 



In writing a natural history of animals, the author proposes, that there may 

 be a threefold account given; a physiological, an anatomical, and a medical; 

 and these taken rather from autopsy than books, and of our own country, rather 

 than the whole world ; and to begin from the lowest degree of animation in 

 zoophytes, or plant-animals, so ascending by nature's clue, to run through all 

 the several tribes of animals, observing the harmony she keeps, or the liberty 

 she takes in the various formation of them. 



In the mean time he wishes that we had a good account of some of the most 

 anomalous and heteroclite sorts of animals, or of those whose species are most 

 diff'erent ; for one of these may serve in a great measure for those of the whole 

 genus, as the anatomy of a porpus for the cetaceous kind. In the anatomy of 

 the porpus he observes, that it is of great affinity with dolphins; that ifc-is vivi- 

 parous, lactiferous, and stands in need of respiration, like land quadrupeds. 

 That internally it so much resembles them, that there is very little difference in 

 the make and formation of the viscera of both; but of several parts here the 

 structure is most remarkable; as of the fat or blubber, which is only oil con- 



