200 ANNUAL OF SCIENTIFIC DISCOVERY. 



come heavier than air, and will then enter every interstice. By pla- 

 cing the pot of burning sulphur in an empty barrel, and inverting over 

 it a barrel filled with potatoes having a light rack in place of a head, 

 the fumes will slowly rise within and impregnate the mass ; the bar- 

 rel and contents being then removed, and the head replaced, the expo- 

 sure may be considered as ample. Where the quantity is large, it 

 would be more economical to leave a space vacant below the loose 

 floor on which they repose, and introduce there the fumes, until every 

 part of the heap of potatoes has received a share. It should be re- 

 membered that this application will injure, if not destroy, the vegetat- 

 ing power of the tubers ; and that, although this result may be highly 

 desirable for all that are preserved for foot), those intended for seed 

 should not be so treated." 



ON THE OCCURRENCE OF FORMIC ACID IN STINGING NETTLES. 



PROFESSOR WILL, of Giessen, some time since showed that the 

 fluid in the hairs of the procession-caterpillar, which causes an inflam- 

 mation of the skin, as well as the liquid in the poisonous organs of 

 some insects, is nothing else than formic acid. It became highly 

 probable, therefore, that formic acid would also occur in the vegetable 

 kingdom, and the first class of plants which was thought of was that 

 which, by means of stinging hairs of similar organs, produces an 

 analogous effect to the sting of certain insects. Acting on this sug- 

 gestion, Dr. Gorup-Besanez has succeeded in detecting the presence 

 of formic acid in various stinging nettles. It exists in minnte quanti- 

 ties, and is supposed to be contained only in the stinging hairs, an as- 

 sumption which is confirmed by microscopical observations, since, 

 when a solution of silver is applied to the plant under the microscope, 

 and a gentle heat applied, reduction always first occurs at the ex- 

 tremity of the stinging hair. London Chemical Gazette, Jan. 1. 



CONCENTRATED ANIMAL MANURE. 



A PATENT with this title has been ordered to issue ; but from delay 

 in amendment of the ciairns it will not be published in the list of 1849. 

 Its importance, however, embodying as it is believed facts and princi- 

 ples not hitherto generally known, demands some notice. To express 

 a principal feature of the invention in few words, the inventor exposes 

 the flesh of animals to the action of sulphuric acid of certain strength, 

 by which it assumes a fixed state or condition, in which it may be kept 

 for any length of time, without undergoing any further change. In 

 this state the animal matter may be preserved for transportation, for 

 manure, or for the manufacture of ammoniacal salts. The inventor in 

 his description says, " My invention has for its object the production 

 of a concentrated manure, with nitrogen as an aliment, to be used as a 

 substitute for guano. In the preparation, I make use of such organic 

 substances as, whenever employed for manures at all, have been at- 

 tended with the production of much nauseous effluvia, and the loss of 

 a great part of their substance by the escape of the gases evolved, and 



