164 Notes and Memoranda. 



Becquerel. I conceived the idea of covering the chloride film, .before exposing it 

 to the light, with a layer of a saturated solution of chloride of lead mixed with 

 enough dextrine to form a varnish." He found that the colours were produced 

 with greater brilliancy on a plate thus prepared, and after their appearance the 

 plate was heated over a spirit-lamp, not raising the temperature high enough to 

 carbonize the varnish. " Under the influence of heat, the colours usually grow 

 more intense, especially if the light has influenced the whole thickness of the 

 chloride of silver ; but if otherwise, the blues are turned into violets, and the 

 blacks to reds." The result of the process is, " that the destructive action of 

 light upon the plate is retarded, so that ten or twelve hours are necessary to 

 destroy the colours, winch, under ordinary circumstances, would disappear in a 

 few minutes. Such is the state of heliochromy to-day, and if the problem of 

 fixation is not yet solved, we may at least hope for a solution." M. Chevreul 

 remarks that the discovery of the dextrine and chloride of lead varnish is a great 

 advance, and he 'compares the sensitive films of M. St. Yictor to the retina of 

 the human eye. 



A Living- Skeleton. — Under this title a very remarkable monstrosity is ex- 

 hibited at Lima, in Peru. The individual, whose name is Montaos, appears about 

 thirty-five years of age, but he says he is only twenty-eight. He seems to enjoy 

 good health, his complexion is rosy, his cheeks full, and his eyes bright. His arms 

 are long and fleshless, his body flattened, the legs dried and bent up like those of 

 a Peruvian mummy, and terminating into two small half-bent feet. He has 

 never been able to stand, and presents himself for exhibition seated on a three- 

 legged stool. Notwithstanding his unfortunate organization, he contrives to play 

 the violin and accordion with considerable taste. His body has a slight power of 

 motion backwards and forwards, and he is able to use one hand and arm. To 

 play the violin, he fixes one end of the bow between his legs, and steadies the 

 other with the upper part of his body. He then takes the instrument in his 

 right hand, fingers the strings, and at the same time draws them across the bow. 

 The accordion he manages by securing the loose portion between his body and 

 left leg, his mouth seizes the upper part, and the fingers of the right hand touch 

 the keys. — From the " Carrier cio de Lima" January 3, 1862. j 



Ctteiotjs Effect op Vis ineb.ti.e. — M. Tardiret states that if a perfectly 

 smooth and polished plate of glass, ivory, or metal is caused to rotate with great 

 velocity in a horizontal plane, it does not communicate its own motion to a 

 highly-finished ball which may be placed upon it. 



Action of Iodine on Tin. — In the Comptes Rendtis (January 27th 1862) 

 will be found a paper, by M. Personne, on the iodides of tin. To obtain a direct 

 combination of the two substances, he placed 21 grammes of iodine and 10 grammes 

 of powdered tin in a sealed tube. At about -\- 50° cent. (122° Fahr.) a violent action 

 took place, accompanied by the evolution of light. After cooling, the tube was 

 broken, and there was found in it a metallic button of tin, and a red substance 

 highly fusible and volatile. This was the bi-iodide of tin SnP. This substance 

 crystallizes in octahedra of a red-orange colour. It melts at -\- 146° cent. 

 (294-8° Fahr.), and emits yellow vapours; at|+ 142° cent. (287'6 D Fahr.) it solidifies. 

 After vaporization, it condenses on cool bodies in beautiful needles, resembling in 

 form those of sal ammoniac. It is decomposed by water, into hydriodic acid, and 

 binoxide of tin. It dissolves in bisulphide of carbon, chloroform, and benzine, 

 and likewise in anhydrous alcohol or ether ; but, like bichloride of tin, it can 

 enter into combination with these last solvents. It absorbs ammonia, and forms 

 three compounds. The protoiodide of tin is obtained by dissolving powdered tin 

 in concentrated hydriodic acid, or by a double decomposition produced by pouring 

 a solution of protochloride of tin into a moderately strong solution of iodide of 

 potassium. In concluding his paper, M. Personne observes that it results from 

 the experiments which he details that the action of iodine on tin is precisely 

 similar to that of chlorine or bromine on that metal, and the iodides of tin are 

 analogous in composition and chemical properties to its chlorides and bromides. 



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