148 



north and south to such a degree that these points "of the compass can 

 readily be determined from their examination. This statement has, 

 however, been contradicted by others, who are unable to find any ten- 

 dency of the kind iu question. In a recent paper by Mr. Meehan, of 

 Philadelphia, the discrepancy is reconciled by stating that the pecu- 

 liarity is only appreciable in the young plants and when they first come 

 up, since, after becoming large and heavy, they are moved out of place 

 by the wind and rain, and unable to regain their original position. 



Uses of the "watee-pest" plant. — Much alarm has been caused 

 in Europe by the spread of a certain plant, living in running Avater, 

 called the water-pest, {Elodea canadensis,) and said to have been intro- 

 duced from America. By its very rapid growth it speedily chokes uj) 

 the channel-ways, thus impeding the flow of water in mill-races, and 

 interfering also with fishing, A recent German writer, however, finds 

 consolation in the fact, which he thinks he has ascertained, that this 

 " v,\iter-pest" exercises a ver^- important function in purifying the water, 

 and that if planted in streams v;hich form the drainage of sewers, it will 

 take up entirely and destroy any disagreeable smell, as also the noxious 

 I)roperties of ordinary sewerage. The composition of its ashes is said 

 to be extremely com})licated, and the plant itself is recommended as 

 furnishing a manure of the greatest value. It has also been tried Avith 

 success in paper-making. 



Circulation in plants. — In conducting experiments upon the tran- 

 spiration of fluid by leaves, it is a matter of importance to determine 

 the rapidity of ascent of the fluid. Professor Church suggests for this 

 case the use of lithium citrate, a salt easily taken up by plants, and one 

 which can be detected with the greatest readiness by means of the spec- 

 troscope. Its advantages consist in its containing an organic acid, and 

 in not being likely to meet with any obstruction to its passage from the 

 tissues. An experiment has lately been made with this liquid, as sug- 

 gested, with great success ; in one instance the fluid having risen nine 

 inches in thirty minutes, in another five and a half inches in ten min- 

 utes. This is thought superior to the use of coloring matters, which 

 seemed to experience considerable resistance in their passage through 

 the vessels. 



Preservation of milk in railway transportation. — Among the 

 lirecautions taken by an extensive milk comi)any, near Loudon, to insure 

 the safe transportation of inilk and cream by railway, that to which the 

 most importance is attached consists in the cooling of it to the tempera- 

 ture of 50° to 59° Fahrenheit before filling the cans. Should the milk 

 be placed in the cans at a higher temperature, as from 70° to 82°, the 

 motion of the cars will cause the butter to separate as well as to produce 

 a deposit of caseine, which change need not be apprehended when milk 

 is at the lower temperature indi(;ated. A further requirement is to have 

 the vessels completely filled with the milk, and closely fastened. Some- 

 times a small proportion of bicarbonate of soda is added to the milk in 

 hot weather, with important results iu preventing it from turning sour. 



Destroying larv^ of cock-chafer. — It is said that the destruc- 

 tive larvGB of the cock-chafer, which, both in this country and in Europe, 

 does so much damage to pastures, by devouring the roots of grass and 

 causing the death of the sod, may be exterminated by applying to the 

 places affected water in Avhich petroleum has been stirred. The same 

 treatment is also recommended in other instances where it is desirable 

 to keep down the ravages of insects on plants. Applied in this way 



