128 PHILOSOPHICAL TRANSACTIONS. [aNNO I674. 



first published An. l663; and is again newly addressed to his Majesty. In two 

 or three sheets it contains, I think, a great treasury. 



V. A Discourse of the Fishery, briefly laying open not only the Advantages 

 and Facility of the undertaking, but likewise the absolute Necessity of it, in 

 order to the well-being both of the King and People; asserted and vindicated 

 from all material objections, by Roger L'Estrange, Esq. In one single sheet, he 

 says, in our opinion, more to the purpose than some would have done in a large 

 volume. 



Considerations of M. Xeeivenhoek, touching the Compression of the Air. N° 102, 



p. 21. 



In this paper, M. Leewenhoek describes an experiment he made to compress 

 air, or rather, as he erroneously imagined, to force it through solid glass. He 

 took a long tube of glass, close at one end, and a plug or piston to fit it very- 

 tight, that so the air might not escape by the side of it. By pushing this plug 

 into the tube, full of air, with much force, he was able to force it to within the 

 100th part of the length of the close. Whence, instead of inferring that the 

 air was compressed into the 100th part of its space or volume, he concluded that 

 he had forced nearly all the air, through the pores of the solid glass. 



More Microscopical Observations made hy the same Leewenhoek. N° 102, p. 23. 



I have observed by the microscope, that blood consists of small round globules, 

 driven through a crystalline tiumidity or water. I have likewise observed some 

 of the sweet milk of cows, and find that also to be made up of small transparent 

 globules, carried in the same manner as in the blood through a clear liquor. I 

 observed the hair of an elk, and found it wholly to consist of conjoined glo- 

 bules, which by my microscope appeared so manifestly to me, as if they could be 

 handled. And therefore having so clearly seen those globules, I assure myself, 

 that the growth and increment of hair is made by the protrusion and driving on 

 of globules. This hair of the elk I find to be within much hollower, than that 

 of men or of other animals. Again, I also observed a nail of my hand, and 

 found it likewise to be made up of globules, not doubting but that it also grows 

 from globules protruded. Having formerly spoken of the louse, her sting, &c. 

 I cannot here omit to say something of what I have seen within that creature. I 

 have several times put a hungry louse upon my hand, to observe her drawing 

 blood from thence, and the subsequent motion of her body, which was thus : 

 the louse having fixed her sting in the skin, and now drawing blood, the blood 

 passes to the fore part of the head in a fine stream, and then it falls into a larger 



