CHEMICAL SCIENCE. 285 



cess," when treated in the same manner, show evident signs of the pres- 

 ence of a carbonate. 



It would seem as if all that is needed to obtain as good a reputation for 

 the American madders as any in the world, is to have them ground on 

 the French process, which, from the deportment of the different varieties 

 of madder when treated with carbt. lime, would lead to the supposition 

 that there is a certain amount of carbt. lime added to the best French 

 roots during the process of grinding. 



There seems to be a fair inducement for the farmers and growers of 

 New England to cultivate madder ; for although Mr. Clapp labored under 

 many disadvantages, such as building and procuring an entire set of ap- 

 paratus, drying kilns, &c., and obtaining but about one-third of a crop 

 from his land as compared with the crops raised in Western New York, 

 still he lost only the interest on the land cultivated. 



ON THE ANALYSIS OF THE ASH OF LEMON JUICE. 



In a communication to the London Chemical Society, Mr. "Witt referred 

 to the difference of opinion as to the cause of the value of lemon-juice as 

 an anti-scorbutic, some attributing its effect to the acid, and others, with 

 Dr. Garrod, believing that it supplied potash to the constitution of the 

 patient. The author had found forty-four per cent, of potash in the ash, 

 along with lime and other substances. The whole quantity of the alkali 

 in the juice was very small, only 1.7 grains in 1000 of the liquid. Dr. 

 Bence Jones expressed his conviction that the action of this remedy was 

 not due to the very small quantity of potash it contained, but rather to 

 the citric acid, which had an effect upon the system analogous to, but much 

 less than, that of oxalic acid. 



PREVENTION OF THE RAVAGES OF THE SHIP WORM. 



A plan for the preservation of submerged timber from the attacks of the 

 " worm " has been devised by Mr. Swan, of California. He claims that 

 it is both cheap and effectual, and a committee has been appointed by the 

 California Academy of Natural Sciences to investigate the matter. A ma- 

 rine railway to which it w r as applied remains, at the end of eighteen 

 months, perfectly sound ; while timber by its side, or the same species of 

 wood, has within that period twice required renewal, having been fairly 

 " riddled " by the Teredo. It is simply the application of a mixture of 

 asphaltum, (one hundred parts,) sulphur, (forty parts,) and arsenic, 

 (twenty parts,) used as a paint, the asphaltum being melted, the other 

 materials stirred in, and the whole applied hot with a common brush ; 

 the wood must of course be dry. If this proves to be as effectual as the 

 trial here seems to promise, the value of the discovery can scarcely be 

 overrated. Com. to Bos. Society Nat. His.) by Dr. Aijres. 



