72 EIGHTH REPORT — 1838. 



rollers, and then returned again into the pit for a fresh supply 

 of tanning liquor ; such liquor becomes exhausted, about tAvo degrees 

 of the barktrometer, in twenty-four hours, when it is pumped to 

 the next pit backwards of the series ; and, by the time it arrives at the 

 last pit, (eight days,) it will have lost from 16 to 20 degrees by the 

 same instrument. The eight pairs of rollers require one-horse powe;r 

 to work them, and two boys of 2s. 6d. a week each to superintend 

 them ; when two bands or one hundred hides will be taken off weekly, 

 as one month is sufficient for them to be on the rollers. They are now 

 laid by in strong solutions for another month, when they are found to be 

 completely tunned; weighing 10 per cent, more than if they had been 

 operated upon in the old way, while the leather has more soft elasti- 

 city, and is ten times more impervious to water. 



" The levers are loaded according to the state of tannage, and the 

 liquors are changed once a day, making twenty-four changes in the 

 whole, which is about one-fourth of the number formerly used." 



The author entered into a minute statement of facts to prove the 

 practical advantages of the process thus briefly describfd, in respect of 

 cheapness, expedition, quick return of capital, and quality of the pro- 

 duct. 



On some Neiv Salts of Mercury. JBy William West, Leeds. 



This paper describes the composition and properties of some salts, 

 composed of bicyanide of mercury, with the haloid salts of potassium. 



As these salts had, without Mr. West's knoAvledge, been previously 

 formed by other chemists, it is unnecessarj^ to detail his experiments, 

 which confirm former researches as to their composition. The author 

 observed that the pearly lustre of some of these crystals, especially those 

 from the bromide, was such that they might probably be employed in 

 place of the scales of the Bleak, for the manufacture of artificial pearls. 



On a Nciv Compound of Carbon and Hydrogen. By William 

 Maugham, Lecturer on Chemistry at the Royal Gallery of Practi- 

 cal Science, London. 



The compound in question is produced when, the electrodes of a vol- 

 taic battery are amied with charcoal points, and these points introduced 

 into a vessel of distilled water. The points should be attached to the 

 copper-wire electrodes by means of platinum wires. On bringing the 

 charcoal points together under the water, so as to produce the elec- 

 trical spark with as little interruption as possible, the Avater undergoes 

 decomposition, carbonic oxide is produced, and a compound, not pre- 

 viously noticed, consisting of carbon and hydrogen, is at the same time 

 formed. Neither hydrogen nor oxygen gases are obtained as happens 

 when the action is electrolytic. 



The compound under consideration is of an oily nature ; it imparts 



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