72 ANNUAL OF SCIENTIFIC DISCOVERY. 



process is carried to its highest state of perfection, because the tinned iron 

 plate is made of the very best wrought iron. Furthermore, a saving is 

 made of all the tin upon the scrips which for many purposes, improves 

 the quality of the lead ; but it is easily separated if desired. Another ad- 

 vantage arises from the thinness of these scraps ; they present so much 

 surface that part of the iron is oxidized, and makes an excellent flux, 

 thus saving the addition of an artificial flux and reducing the time required 

 for smelting very materially. The waste product used in this process has 

 until now been thrown away. 



NEW USE FOR INFUSORIAL DEPOSITS. 



"In the lakes of Sweden there are vast layers of iron oxide almost ex- 

 clusively built up by animalcules. This kind of iron-stone is called lake- 

 ore. In winter the Swedish peasant, who has but little to do in that 

 season, makes holes in the ice of a lake, and with a loivj; pole brings up 

 mud, &c. until he comes upon an iron bank. A kind of sieve is then let 

 down to extract the ore. One man can raise in this manner ab mt one 

 tun per diem. Besides the excellent polishing material furnished by these 

 infusorial deposits, Liebig has recently drawn attention to another appli- 

 cation of which they are susceptible. His observations were made upon 

 an infusorial deposit which constitutes the under soil of the commons or 

 plains of Liineburg, in Germany; and he his shown tbat these microscop- 

 ic remains, as well as those tiken from several other localities, can be 

 very easily convened into .5 ilicate of potash or silicate of soda, some- 

 times known as 'soluble glass.' It was first ascertained by analysis that 

 this infusorial earth contained 87 per cent of pure silica. The following 

 method was then adopted to convert it into silicate of soda: 148 pounds 

 of calcined carbonate of soda are dissolved in five times their weight of 

 boiling water; to this is added a milk of lime, prepared with 84 pounds 

 of quicklime. After boiling the mixture for ten minutes or a quarter of 

 an hour, the alkaline liquid, which now contains caustic soda, is decanted 

 off from the insoluble carbonate of lime, and evaporated in an iron vessel, 

 until it has acquired a specific gravity of I'lo. At this moment 240 

 pounds of the infusorial earth is added. The latter dissolves rapidly in 

 the alkaline solution, and leaves scarcely any residue. If by any accident 

 a smaller quantity of infusorial earth than that prescribed be taken, the 

 soluble glass obtained is too alkaline and very deliquescent." 



SILK NATURALLY DYED. 



Some experiments of an interesting character have recently been made 

 in Italy, with a view of causing the silkworm to produce silk ready dyed. 

 On this point we know that when certain coloring matters extracted from 

 the vegetable kingdom are mixed with the food of animals they are 

 absolved without decomposition and color the bones and tissues of the 

 body. Starting from this foct, Messrs. Uarri and Alessandrini, in Italy, 

 sprinkled certain organic coloring matters over the mulberry leaves on 

 which the silkworms were feeding. M. Roulin, in France, employed in 

 the same way the coloring matter known as chic a. These attempts have 

 met with partial success only, up to the present time. Colored cocoons 

 were however thus produced several tim?s. Some observers assert, how- 

 ever, that the silk was not really secreted in a colored state, but that the col- 

 oring matter sprinkled on the leaves merely adhered to the body of the 

 grub and colored the cocoon mechanically during its construction. This 



