28 



ing now lasted, in some instances, for as many as twenty years, without 

 any a])itnrent (.'hankie in the wood. 



This is in confirmation of the special report of the Acaden)y of Sciences 

 of Amsterdam, npon exi)eriinents made by the direction of the Nether- 

 lands government. Similar experiences seem to have resnlted from the 

 creosoting- of wool for railroad purposes, as well as for gun-carriages 

 and other engines of warfare. 



The report of Captain Cram discusses the general theory of the appli- 

 cation, and the methods of subjecting wood to the desired treatment; 

 and it is maintained by him that its application to breakwaters. Gov- 

 ernment wharves, piers, and other Government constructions on the 

 lakes, and on the sea-coast, will result in an enormous saving of 

 expense. General Gilmore, in an appendix. to the report, expresses his 

 0])inion that the Bethell process, with its American modification of the 

 Seeley & Kobbins processes, is cheaper and more ettective tlian any other, 

 this consisting essentially in impregnating the timber by boiling it in 

 coal-tar with carbolic acid. 



liusT IN WHEAT. — It is at present well established that rust in grain 

 is produced from the spores of a microscoi)ical fungus growing upon the 

 barberiy and various rough leaved plants, alder, «&c. These, falling 

 upon the leaves of the cereals and other grasses, develop very rai)idly, 

 and in turn yield the summer spores of a similar character, by which the 

 affection is propagated with inconceivable quickness. The winter 

 spores, which are jjroduced last, form on the first-named i^lants other 

 fungus growths the next year, and thereby secure the continuance of the 

 rust from season to 'reason. 



The proper methods of preventing grain from taking this affection, 

 consist, first, in extirpating the barberry and other trees mentioned 

 from the vicinity of the grain-fields; next, the grain should be cleaned 

 with the utmost care, so tliat no seeds of the fungus-bearing plants may 

 be introduced into the field in the sowing, and thus aid in the develop- 

 ment of the disease; and finally, no manure should be ai>plie<l to the grain- 

 fields in which any straws are mixed that have come froui rusted plants, 

 and, in fact, straw of this character should be burned as the njost effect- 

 ual nu4hod of protection against the spreading of the disease. If used 

 at all as manure, however, it should be kept for grass-lauds or fields in 

 whi(di grain is not raised. 



Water glass fou budding teees. — An important use of water- 

 glass is made in budding trees, for which i^urpose it is to be mixed with 

 finely powdered whiting or finely silted chalk into a paste, and the 

 wounded parts of the tree covered with it. In this way the exposed sur- 

 faces will be com})letely protected against the action of the weather, and 

 by timely application and ju'oper manipulation all injurious results from 

 the operation nui,v be avoided. 



Extraction of ammonia from the atmosphere by humus. — In 

 the course of certain experiments made by Bretschneider upon the ex- 

 traction of ammonia from the atmosphere by humus substances, he came 

 to the conclusion that the anitrogenous, brown, organic combinations 

 which are obtained by boiling a solution of sugar with dilute suli)huric 

 acid have the property, when moist, of extracting ammonia, in a dry 

 season, from an atmosphere poor in ammonia; second, that this absorp- 

 tion of amnu)nia, although relatively slight, is yet incomp.irably greater 

 than the power of absorption of a surlace of water for the amnu)nia 

 contained in the atmosphere, and also incom])arably greater than that 

 of nu)ist quartz; third, if the brown combinations are mixed in ascend- 

 ing proi)oitions, without quartz, so that the former constitute 1, 3, and 



