220 ANNUAL OF SCIENTIFIC DISCOVERY. 



same length as the cotton rovings, so as to be able to card and spin 

 them on the machines constructed for cotton. Besides, he wishes it to 

 be supposed that, by placing the flax thus cut up, after it has been 

 boiled in a solution of bi-carbonate of soda, into sulphuric acid diluted 

 with water, it will split, from developing carbonic gas, in appearance 

 resembling cotton. M. Claussen has started a company with a capital 

 of 250,000 to 500,000, to carry on the manufacture, and he exerts 

 every possible effort to obtain purchasers for his patent. To exhibit 

 his patented process of splitting the flax, he has rented a place at 

 London, where M. Ahnesorge (who is never named) has first to 

 prepare the flax or tow by boiling it in a solution of soda, and where 

 afterwards, the experiment of chemical effervescence is made before 

 visitors. This is called the splitting process. 



INI. Hamel declares it to be impossible to change the flax into a fibrous 

 matter resembling cotton, which is the work of nature. He is decidedly 

 opposed to the project of cutting up the dressed flax into a sort of tow. 

 The superiority of flax over cotton consists, in a great measure, in 

 the greater length of its fibres. The result, therefore, would be to 

 convert a primary valuable material into a very inferior one. 



PREPARATION OF CYANIDE OF POTASSIUM. 



M. CLEMAN, of Paris, gives the following detailed account of the 

 process for obtaining this salt in a pure state, the accomplishment of 

 which is a matter of some difficulty : 



Mix intimately eight parts of ferro-cyanide of potassium, perfectly 

 de-hydrated by calcination, and three parts of perfectly dry carbonate 

 of potash, and heat the mixture in a covered crucible, or what is 

 better an iron pot, until the fused mass attains a red heat, when it 

 will become limpid, and a sample taken out with the rod and cooled, 

 will appear perfectly white, in this state all the ferro-cyanide is 

 reduced. If the crucible be now taken out of the fire, the disengage- 

 ment of the gas ceases when the mass has become a little cool, and the 

 iron which has been separated in the operation so disposes itself, that 

 with a little address and slight tapping of the crucible, the principal 

 part of the cyanide of potassium may be poured off from the iron 

 which remains in the crucible. To obtain the cyanide perfectly free 

 from iron, place it across an iron ladle, pierced with fine holes, and 

 strongly heated beforehand, in a vessel also heated, of greater height 

 than width, either of silver, iron, or porcelain, or even fire ware, but 

 with smooth sides, and let it gradually cool. In this state the ferru- 

 ginous portion may be extracted by means of a sharp instrument 

 from that which is free from iron. The purity of the cyanide of 

 potassium entirely depends on the purity of the materials employed ; 

 the presence of sulphur in the carbonate of potash should therefore 

 be avoided ; the ferro-cyanide of potassium of commerce almost inva- 

 riably contains sulphate of potass, the presence of which is objection- 

 able. The use of purified tartar might perhaps be advantageously 

 substituted for that of carbonate of potash. Should any sulphur be 



