340 ANNUAL OF SCIENTIFIC DISCOVERY, 



And gave the following important fact as to the quantum of food from an 



acre of land : 



Starch. Gluten. Oil. 



Dry matter of potato 3,427 Ibs. 604 Ibs. 45 Ibs, 



Dry matter of wheat 825 185 45 



Thus the total nutriment from an acre of land is 



From the potato 40-76 Ibs. 



" wheat, per cent 10-55 Ibs. 



The preparations of meal and flour, prepared from the potato, and ex- 

 hibited by Mr. Rogers, appeared to be almost alike in appearance to wheaten 

 flour and meal, and excited much interest. 



ARTIFICIAL MILK. 



For some time a liquid has been prepared which is said to have so far the 

 qualities of milk that it is called artificial milk or " lait-viancle." It is pre- 

 pared as follows. Into a Papin's digester three kilograms of fresh pounded 

 bones are put and one kilogram of meat, with five or six times as much of 

 water. The top is hermetically closed ; double sides surround it, and in the 

 cavity between, a current of steam circulates which raises the temperature 

 of the digester up to 140 deg. Fah. At the end of forty minutes after reach- 

 ing this temperature, a stop-cock with a small orifice is opened which lets out 

 a vapor having the odor of broth ; but some seconds after, there issues a 

 white liquid which is nothing but the artificial milk. After this miik has 

 passed out, the digester contains only the meat, the boiled bones, and a soup 

 of inferior quality. The artificial milk resembles milk in color, consistence, 

 odor, and even taste. But in composition it is different ; for it is only an 

 emulsion produced by the fat mixed with the water by means of the gelatine. 

 Although the name artificial milk is not proper, it has some nutritious quali- 

 ties, and for this reason it is now under trial at the hospitals of Paris. 



USE OF ARSENIC IN STEEPING GRAIN FOR SEED. 



Boussingault has communicated to the Annales do Chimie some experi- 

 ments on the use of arsenic in steeping grain for seed. This process has two 

 objects, the one to protect the harvest from disease, the other to prevent the 

 seed from being devoured by vermin. The substances generally used are 

 salt, glauber salt, lime and sulphate of copper. But although these may 

 hinder the development of cryptogamic sporules, they have little effect in 

 preventing the seed from being eaten. The greatest part of the substance 

 used remains in the husk, which the animal rejects. 



The most effectual means is the employment of arsenic ; this not only pre- 

 serves the seed from decay, but if eaten by the vermin, it destroys them, 

 being so strongly poisonous. By using arsenic in a soluble form, such as the 

 arseuite of soda, it may be added to the grain in perfectly definite propor- 

 tions. 



