PHILOSOPHICAL TRANSACTIONS, 483 



The Problems are these tliat follow, 



1 prob. D. p, r, t. Q. j? Res. R^ X p = S. 



2 prob. D. s, r, t. Q.p} Res. S — R^ = P. 



3 prob. D. j&, s, t. Q. r ? Res. -~^ = R. 



4 prob. D. /), 5, r. Q. f ? Res. tziZ = t. 



R 



The third rank concerning annuities anticipated, or bought for a sum in hand, 

 or equivalent thereto, at compound interest discounted, founded on the former 

 of the two axioms above mentioned, and this that follows: 



If the difference and worth be once found, the worth is easily obtained, by 

 subtracting that difference out of the principal, which is ever greater, being the 

 worth of the annuity at that rate for ever. 



1 prob. D. j&, r, t. Q. d} Res. P — R* = D. 



2 prob. D. d, r, t. Q.p} Res. D X R^ = p. 



3 prob. D. p, d, L Q. r ? Res. ^^ = R. 



p.! jy 



4 prob. D. pi d,u Q. t} Res. ^ == t. 



An Account of Books. Philos. Collect, N° 1, p. 38. 



Marcelli Malpighii Phil, et Med. Bononiensis, e Societate Regia Anatomes Plan- 



tarum. Pars Altera. Lond. 1679. 

 This ingenious author having, in the first part of his anatomy of plants, given 

 us the description of the several parts a plant consists of, together with their 

 uses, and the method and order of vegetative motion ; in this second part, he 

 explains the causes and descriptions of the usual accessaries and accidents of 

 vegetables : as, the method of growing, from the first motion of the seed, and 

 what change it daily undergoes, &c. Nexf he shows, that galls, or preternatural 

 tumors of plants, are receptacles or nurseries of the eggs of insects. Then he 

 treats of the excrescences and other morbid tumors from some fault of the plant 

 itself. Then of the hairs or thorns which plants are armed with. And in like 

 manner of the tendrils, or the hands wherewith weak plants lay hold upon some 

 firmer support ; and with no less exactness of the plants that grow upon others. 

 Of roots, and in what manner buds are shot out : and herein of bulbous plants 

 that are but annual, and yet renew and propagate from themselves without the 

 mediation of seeds. And all these things are so illustrated by figures well graven 

 after the author's own exact delineations, that there is hardly any room left for 

 addition. 3 a 2 



