VOL. XXXVI.J PHILOSOPHICAL TRANSACTIONS. 32S 



this seems to be the first time it has been used in Botany. By this means, 

 without a long tedious description, a plant may be known by mere inspection. 

 However, that nothing may be wanting, the author has thought fit to give 

 short descriptions, insisting more particularly on those minute parts which can- 

 not be so clearly expressed by sculpture : and has added, where they could be 

 obtained, some account of their uses, &c. 



A71 Attempt to solve the Phenomenon of the Rise of f^apours, the Formation 



of Clouds, and the Descent of Rain. By J. T. Desaguliers, LL. D. F. R. S. 



N" 407, P- 6. 



Dr. Niewentyt and some others say, that particles of fire separated from the 

 sun-beams, by adhering to particles of water, make up moleculae, or small 

 bodies specifically lighter than air, which, by hydrostatical laws, must rise and 

 form clouds, that remain suspended when they are risen up to such a height, 

 that the air about them is of the same specific gravity with themselves. 



That rain is produced by the separation of the particles of fire from those of 

 water, which last being then restored to their former specific gravity, can no 

 longer be sustained by the air, but must fall in drops. See Niewentyt's Reli- 

 gious Philosopher, Contemplation ig, from Sect. 13 to Sect. 25. 



Now this is liable to several objections. 1st. It is built on a supposition 



Siccus of exotics, containing 26OO specimens; near 250 drawings of Fungi ; his colleclion of seeds 

 and seed-vessels; and his Materia Medica." 



He removed to Chelsea about a year before his death, which event toolt place on the 29th ot 

 January 1768. 



He was the author of the following publications: 



Tabulae Synopticae Plantarum Otficinalium ad Methodum Raianam dispositae, 1726, fol. 



Methodus Plantaram circa Cantabrigian nascentium, 1727, 12mo. 



Historia Plantarum Rariorum Decades Quinque. Fol. max. 1728, 1732. This was the most 

 -sumptuous and magnificent work of the kind that had ever been attempted in England. 



Toumefort's History of Plants growing about Paris, with their uses in Physic, 2 vols. Svo. 1732. 



The Compleat Herbal of Dr. Tournefort, with large additions from Ray, Gerard, &c. &c. 2 vols. 

 4to. This is a translation of Toumefort's Institutions, accompanied by plates, copied from the ori- 

 ginal. It proceeded no fanher than the 2d vohime. It is a work of great merit; and with the as- 

 sistance of the plates, must have greatly tended to facilitate the study of Botany in England. 



The papers published by Dr. Martyn in tlie Philosophical Transactions we need not here enume- 

 rate, since they will appear in their respective periods of time. 



Dr. Martyn was also greatly concerned in preparing tiie old Abridgments of the Philos. Trans, 

 having, in conjunction with Mr. Eanes, published the Abridgments from the year 17 IP to 1733, in. 

 2 vols, being the 6th and 7th; and by himself prepared the remainder, till the year 1752, in 4 other 

 volumes, being tlie 8th, pth, 10th, and 11th volumes of the Abridgment. 



He was also connected with Mr. Chambers in publishing an Abridgment of the Memoirs of the 

 Academy of Paris, in 5 vols. Svo. in 1742. 



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