iistly valuable, all tlie French Journals 

 iiulicc what they call Lithochromy, 

 as well deserving of attention. This 

 art is, evidently, an application of 

 lithography ; as yet, however, it is 

 young, and dors not appear (o the most 

 iidvantage, ti)ougi) susceptible of im- 

 provement. Lithochromy not only de- 

 signs figures of stone, but undertakes 

 to imprint colours on linen, white, 

 red, green, &o. wilh sliades varied, ad 

 inftnilum. M. Malapcan, obtained a 

 patent for this invention two years ago, 

 and exhibits p\ibiicly a number of 

 lilhochromio productiuns. His exer- 

 tions have tinned to account, but his 

 ))iuces, though pleasing and agreeable, 

 are thougiit, in point of (piality, to be 

 only in a stage of progression towards 

 licrfcetion. He dcsiguates his process 

 as painting with oil on stone, and as 

 jninling on linen, as well as painting 

 with oil. Nothing further has trans- 

 pired respecting the means he employs, 

 tlie r<'st is kept secret, and the inventor 

 juay have his reasons for so doing. 



In ciuliualiiig cucumlters or water- 

 melons, it has been ascertained, that 

 a very low and long-continued tem- 

 perature causes the plants to produce 

 on\\ female flowers, and so they prove 

 iniproductive of fruit; and on the con- 

 trary, too iiigli and long-conliiujed a 

 1cm|)eratnre, produces only male flow- 

 ers, alike unproductive. Mr. F. Andrew 

 'Knight, from these experiments, enter- 

 tains but little doubt, that the same 

 fruit-stalks of these two plants, and 

 perhaps others, might be made to pro- 

 duce either male or female flowers, in 

 obedience to external causes. 



Mitallic Titanium is prohally not 

 magtietic, when unalloyed Ity iron. 

 Dr. Wollaston, in experimenting upon 

 the small cubes of titanium, found in 

 cavities, adjacent to the hottest places 

 of our tall iron furnaces, (see our 65tli 

 vol. p. 171,) in which the common 

 argillaceous iron-stone of the coal 

 measures is reduced, he foimd small 

 jiarticles of iron slug adhering to the 

 cubes ; by disj)Iacing of which par- 

 ticles, he succeeded in so far reducing 

 the susceptibility of the Cubes to the 

 magnet's action, that ihe Doctor hence 

 concluded titanium to be non- magnetic: 

 this, however, ap])earing to some others 

 as a doubtful position, finther expe- 

 riments have been m.adc, from whence 

 Dr. W. infers, tiiat the usual tests of 

 the presence of small proportions of 

 iiOD, as an alloy of titanium, arc so de- 



Spirit of Philosophical Discovert/. [Alay 1, 



fcctive, as not to be able to detect l-2601h 

 part of iron, and yet this very small 

 proportion, the Doctor shews, would be 

 sufficient to account for all the mag- 

 netic properties of the metallic cubes 

 in question; and that, therefore, pure 

 titanium is probably non-magnetic. 



The copper-sheathing of ships in tlie 

 royal navy has been found subject to 

 a rapid corrosion and decay, which has 

 occasioned the Jjortis of the Admiralty 

 to consult Sir H. Davy thereon, who, 

 after a series of experimentsj has re- 

 commended the fixing of small masses 

 or wires of tin, or of some other of the 

 readily oxidable metals, in contact 

 with the coppcr-sheati)ing: by which 

 simple means, it is expected that the 

 copper will be rendered so negatively 

 electrical, that the sea-water will have 

 no action upon it. 



The indications of returning spring 

 on the North American Continent, at 

 one hundred miles from the sea-coast, 

 as observed and averaged by Dr. 

 Coolcy, at Dcerfield, lat. 42° 18' N. 

 in the live years ending with 1819, were 

 as follows, viz. the martin and barn- 

 swallows first appeared, 24th April; the 

 forests of oak, chestnut, maple, and 

 birch, at the distance of half-a-mile, 

 first shewed ajipearance of foliage, 

 12th May; the common red garden 

 cherry tree in full bloom, 14th May ; 

 the red-currant bush in full flower, 

 16th May; and the apple-tree in full 

 bloom, 27th May. From our ingenious 

 correspondents who may long and 

 regularly have recorded facts of the 

 above nature, averages of the above 

 concise kind would be very accept- 

 able. 



The formation of ice upon ponds, 

 during continued Irost, proceeds in a 

 decreasing scale, as to the additional 

 thickness added below, during each 

 succeeding night, of equal intensity of 

 cold ; this fact, so important as an 

 indication of the infinite wisdom and 

 goodness of the Creator, received a 

 satisfactory proof from the observations 

 of Professor Silliman, during twenty- 

 one days of excessive cold,in the winter 

 of 1820-1: the mirmte bubbles of air, 

 arranged in strata, at the top of each 

 nigiit's fresh ice, showed a pretty re- 

 gular decrease of daily thickness, from 

 about one and half inches to about 

 half an inch, owing to the very slow 

 conducting power of ice. This, and the 

 extraordinary j)ro|)erty of water, to 

 begin to expand ngain in bulk whilst 

 progres- 



