207 



"would appear, however, from Dr. Calvert's experiments, that carbouic 

 acid is the principal agent, and that without this the other agencies 

 have very little eitect. Iron does not rust at all in dry oxygen, and but 

 little in moist oxygen ; while it rusts very rapidly in a mixture of moist 

 carbouic acid and oxygen. If a piece of bright iron be placed in water 

 saturated with oxygen, it rusts very little; but if carbonic acid be 

 present, oxidation goes on so fast that a dark precipitate is produced in 

 a very short time. It is said that bright iron placed in a sohition of 

 caustic alkali does not rust at all. The inference to be derived is that 

 by the exclusion of moist carbonic acid from contact with iron rust can 

 be very readily jn^e vented. 



Propagation of the grape by eyes. — A German agricultural 

 journal informs us that the grai)e-viue can be propagated by means of eyes, 

 so as to save three years' time in the growth, each «ye furnishing a new 

 shoot. Each grape-vine will furnish as many shoots as it has sound 

 eyes, and they are to be cut off about a quarter of an inch from the eye 

 on each side, so as to leave a cylinder of wood about half an inch long, 

 with the eye in the center. If prepared in the autumn, these eyes may 

 be put in a cellar in winter. In April they are to be laid down at a 

 depth of two or three inches in furrows about six inches apart, and 

 covered with a little manure, watered in dry weather, and the earth 

 about them occasionally loosened. 



Curing dampness in walls. — A Russian preparation for curing 

 moisture in the walls of houses consists in the use of a mixture made by 

 adding two i^ounds of white resin to a boiling solution of thi^e and 

 three-fourths pounds of green vitriol in one hundred pounds of water. 

 To this ten pouuds of isifted red oclier, or other color, eight pounds of 

 rye meal, and six and a half i)ounds of linseed oil are to be added, and 

 the whole stirred together until it forms a completely homogeneous 

 mass. Two coats of this mixture are to be applied successively, while 

 hot, but only in dry, warm weather. 



Manure from dead animals. — Dead animals are utilized in France 

 by immersing their soft parts in a very feeble solution of hydrochloric 

 acid, which soon transforms them into an odorless pulp. This is to be 

 mixed with phosphate of lime, and the result is a manure of the best 

 quality. x 



Utilizing the grease of sheep's wool. — An additional instance 

 of the possibility of converting what was formerly considered refuse into 

 valuable material, is seen in the case of the fatty matter contained in 

 sheep's wool, and technically known as suint. This contains about 40 

 per cent, of potassa, and when ignited the alkali becomes entirely mixed 

 thereby with strongly-nitrogenized animal charcoal. The result of re- 

 cent experiments tends to show that suint, thus treated, may be used to 

 an excellent profit in the manufacture of prussiates aud cyanides. 



Utilizing fish offal. — An ingenious method, lately proposed, for 

 utilizing the residue and offal of tish, consists in first boiling it together 

 with one-tenth of its weight of cheap oil, heating it up from 250° to 

 300° F. It is then treated with sulphide of carbon, whereby the oil naturally 

 contained in the fish, as well as that which was added, is extracted, and 

 a mass is left, quite dry, and containing from 5 to per cent, of nitro- 

 gen, and from 12 to 15 per cent, of phosphate of lime. 



Marks of difference of sex in eggs. — It is stated that the eggs 

 of the common hen, as well as those of nmiiy other birds, present cer- 



