I909-] Summary of Agricultural Experiments. 



69 



The experiments showed that apple juice can be sterilised in wooden 

 containers, such as barrels, kegs, &c, in which it was found that 

 the product remained sound for six months. The juice so prepared 

 was palatable, and acceptable as a summer drink. The use of 

 tin vessels, which can be sealed by a mechanical process, excluding 

 all metals except the tin of the can from contact with the juice, was 

 also successful. Apple juices were canned and sterilised by heating 

 in hot water up to 149 0 F. These juices possessed only a slight cooked 

 taste due to the heating, and retained much of their distinctive apple 

 flavour. It was found that from finely flavoured apple juice a first- 

 class sterile product could be made, while a poorly flavoured apple 

 juice yielded an inferior product. The juice can also be sterilised in 

 bottles. In this case the sediment in the juice must be removed, which 

 can be done to a large extent with a cream separator. The results of 

 extensive tests in clarifying the juice by means of a separator are 

 given, and also an account of experiments in carbonating apple juice, 

 and in the use of benzoate of soda as a preservative. 



Absorption by Soils. (US. Dept. of Agric, Bureau of Soils, Bull. 

 52.).— In this Bulletin the work on absorption by soils, which has 

 been in progress in the Bureau for some years, is continued, and a 

 further and more complete study is made of the composition of the 

 solutions and the quantity of material removed from solution by the 

 soil. The literature upon the subject of absorption is also brought 

 together. 



The object of these investigations has been to determine how 

 absorption controls the concentration of the soil solution, which is the 

 nutrient medium upon which plants feed, and, further, to deter- 

 mine the effect of absorption upon the structure of the solid portion of 

 the soil in modifying its power to hold and maintain the soil solution 

 for the continued use of the plant. 



In the experiments described, the materials used have not always 

 been fertilisers or constituents of the soil itself, since other substances, 

 particularly certain dye stuffs, are better for the purpose of obtaining 

 a more detailed knowledge of the mechanism of absorption. It is 

 stated that, in general, where disturbing influences are not great, the 

 rate of absorption and distribution of a material in the soil may be 

 expressed by a mathematical formula. The disturbing influences, 

 however, are important in most cases actually met with in practice. 

 The most important is the change in the physical character of the 

 soil itself, consequent upon the absorption of the dissolved materials. 

 In some cases, notably with acids and with lime, the soils assume a 

 "flocculated" structure, i.e., a great many of the ultimate grains 

 form larger aggregates or "ball together"; and in other cases, 

 especially with alkalies, the soils are deflocculated, each grain standing 

 out separate and distinct from the others. This change in the structure 

 of the soil is of the utmost importance in influencing the physical 

 condition of the soil, which in turn influences the drainage condition, 

 the aeration of the soil, its capacity to hold the soil solution and control 

 its movement through the soil, the composition of the soil solution, the 

 character and rate of the chemical changes taking place in the soil 

 solution ; and, in fact, in influencing directly both the physical and 



