!824.] 



sion. Whctlier Uiis was done in sport, 

 or for escapinij a finny pursuir, it has 

 often been difficult to ascertain. 



Sir EvERARn Home's new theor,y, 

 respecting the physiology <rf the blood, 

 purports, that carbonic acid gas forms 

 a large proportion of the blood, and 

 that tliis fluid is of a tubular texture. 

 It exists in tlie proportion of two 

 cubic inches to an ounce, and is given 

 out in large quantities, from the blood 

 of a person after a full meal, but very 

 little from the blood of a feverish 

 person. The fact, of the appearance 

 of the tubes passing through every 

 particle of the blood, was discovered 

 by Sir Everard (in 1818), on observing 

 the growth of a grain of wheat, daily, 

 through a microscope. He first saw 

 a blob, and then a tube passing from 

 it; the blob was the juice of tlie plant, 

 and the tube was foimcd by the extri- 

 cation of carbonic acid gas. He tlien 

 examined a globule of blood, and 

 found it composed of similar tubes, 

 which he injected under the exhausted 

 receiver of an air pump. His disco- 

 very will probably lead to important 

 results. 



Our Astronomer Royal, who thinks 

 there is no sensible parallax, never- 

 theless infers, from the observations of 

 M. SruuvE, that the mean parallax of 

 several fixed stars carniot exceed 

 0",018; but Mr. Struve assigns U",16 

 as the parallax of eight in the Littlo 

 Bear, and 2",221 as the parallaxes of 

 two others in the Swan and Great 

 Bear. Dr. Brinkley conceives that a 

 sensible parallax may be determined, 

 but Mr. Pond impeaches his iustru- 

 inentit. 



The component parts of Parker's 

 cement appear to. be — 



Carbonate of lime .... -657 



■ magnesia -OO.? 



iron . • • • -070 



manganese 'Oig 



Clay silica •180 



alumina '006 



Water -OVS 



Splrii of Philosophical Discover^/. 77 



taline forms of arllfloial salts, with a 

 view to enable chemists to know and 

 describe, with more accuracy than yet 

 they have usually done, the external 

 forms of the crystals produced in their 

 experimental processes. 



JFood of Bats. — From observations 

 made by M. Swainson, during his 

 residence in the Brazils, it appears 

 that bats do not always feed on animal 

 substances, as is conmionly believed, 

 from the circiunsiauce of the sharp- 

 pointed tubercles \\ith which their 

 molar teeth are bristled. Or, at least, 

 it is certain that he discovered in that 

 country Ciiiropteres of the genus 

 Pteropus, a species that feed only on 

 fruits. M. S. being attached for some 

 time to a plantation in the province of 

 Fernambuco, u as in the habit of re- 

 marking a prodigious number of bats, 

 about tiie time of twilight, flying with 

 great force and rapidity in the middle 

 of a grove of fig-trees, that were 

 covered with their nests. The fmits 

 became the prey of the young, ou their 

 arriving at maturity. 



That hciit increases the power of an 

 electrical machine, has been ascertained 

 by Mr. Ronalds ; who, using a very 

 small spirit-lamp under the rubber, 

 and another under the prime conductor 

 of a cylindrical-glass machine, has 

 very greatly increased its power, and 

 thereby he has been able to render it 

 efiective in the dampest weather. 



The a7iah/sis of Candite, a new black 

 mineral from Candy, in Ceylon, was 

 lately made by Dr. Gmelin, which 

 aH'orded hiin as follows : — 



Alumina < . 57-20 



Iron, protoxide 20 51 



Maenesiki,wilh a trace of manganese 18*24> 

 Silica, piobably accidental . . . 3'16 



fOOO 



With one part of conunon clay, and 

 two parts and a h;df of chalk, a very 

 good hy<lraulic iimo may be made, 

 which will set us speedily as Parker's 

 cement. 



Mr. n. BnooKE, the author of 

 " Elements of Vryslallography," as ap- 

 plied to minerals, has commenced a 

 series of important papers in the 

 "Annals of Philosophy," illustrated 

 by excellent woed-cuts, ou the crys- 



99-n 



Tlie name above chosen seems parti- 

 cularly unfortunate, since the disco- 

 very by M. Sicbers, that the name of 

 Crete Island, in the Mediterranean, 

 was changed to that of Candia, on 

 account of the prevalence there of a 

 white earth (the crela of the ancients,) 

 hetetoforo erroneously su]iposed to bo 

 chalk. 



Gooseberry bushes have, during se- 

 veral years past, been trained by Mr. 

 S. JiLVEES, in the manner of a hcrceau 

 or arbour walk, about five feet and a 

 half wide and seven feet high ; whcre- 

 I)y the fruit, in very increased (ju.mtity, 

 is pleasarilly exposed to the view of 

 company walking under the aiched 

 trellis 



