920 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Slacked lime 200 kilos., cost 2 francs. 



Phosphate of lime 400 kilos., cost 80 francs. 



iS'itrate of soda 500 kilos,, cost 200 francs. 



Carbonate of potash . . . 200 kilos., cost • 190 francs. 



Total 1,300 kilos., cost 472 francs. 



This quantity is required for one hectare, equal to 107,650 

 square feet, or nearly two and a half acres. 



To Determine the Value of Glue. 



Dr. Weidenbusch, after finding, by repeated experiments, that 

 chemical determinations will not answer, devised a physical test, 

 which consists in casting gj'psum of the finest quality into sticks 

 of mathematically exact dimensions by means of moulds of French 

 chalk. These sticks are saturated with solutions of difierent glues, 

 and one by one, placed in a brass ring having two deep notches to 

 receive the stick; and connected, a lever and glass or iron beaker, 

 into which mercury is poured until the stick breaks; thus the 

 amount of mercury used is the measure of the strength of the glue. 

 The author has not been able to ascertain any relation between 

 the tenacity and the specific gravity of glue. Objection may be 

 made to this method in consequence of the difficulty of obtaining 

 sticks of exactly the same size and saturated by the same quantity 

 of o-lue: nevertheless, the process is said to be more satisfactory 

 than the common chemical process of precipitating gelatin by 

 means of tannin. 



The Arrest and Prevention of Cholera. 

 Dr. A. E. Samson, in a work with this title,' advocates a curative 

 treatment of the cholera, which depends on internal disinfection. 

 He takes the ground that if antiseptics are found preferable to 

 oxidizing agents applied externally, they should have the same 

 relative advantage if given internally. We have two agents which 

 fulfill the indications required, to render inert, an organized poison; 

 1. the sulphites; 2. carbolic (phenic) acid. These have their 

 mutual advantages and disadvantages. The first is administered 

 with greater facilities, but is more rapidly metamorphosed into 

 other less efficacious compounds, and, no doubt, has less powerful 

 action upon the germs. The second, on the other hand, has a 

 " stinging" efiect on the sensative surfaces, and its taste is to some 



