EXrEUIMKNTAL STATIONS — HKPOKT FOR 1879. 297 



other thiiit^s, upon tlie .si»lul)ility of tlu' suits in tli(i soil, and it 

 takes ])liice more rajjidly in ])ot.s coutiiinin^' soluble manures. 



By the use of canvas ba.n's all these inconveniences are avoided; 

 the salts do come to the outside in some measure, but the root- 

 lets come out in search of them. Their great ])()rosity favours 

 the deration of the soil, and their thinness causes them to be 

 moistened immediately when the earth is watered, and so per- 

 mits of the watering being conducted with great equalness and 

 precision. The bags were placed in clay flats which, during tlie 

 Avhohi course of tlu^ experiments, were scarcely ever wetted. The 

 manures, of the same kind and amount per acre as those used in 

 the Society's experiments, were mixed into the upper 4 or 5 

 inches of soil, and the barley was sown at an equal depth in all 

 the bags. Great care was exercised in choosing the seed, so as 

 to prevent the occurrence of any dilfcrences in the crop due to 

 imequal seeding. The method adopted was the following : — The 

 barley was first steeped in water, and all that floated was thrown 

 away. Thereafter sugar was added to the water till a thick 

 syrup was formed, in which about three-fourths of the residue 

 floated. This also was set aside, and the fourth part, which 

 remained and constituted the heaviest of the barley, was kept for 

 seed. It was washed and spread out, and separated as nearly as 

 possible into large and small grains. The large grains were 

 selected for the experiments. The pots, forty in number, were 

 arranged on a table in the centre of a green-house, and their 

 relative positions were changed from time to time so as to secure 

 as equal an ex]-)0sure as possible to all the pots. There was an 

 abundant supply of air admitted during the whole season, and 

 care was taken in the watering of the pots that each should get 

 just as much water as it required, those on which the growth 

 was luxuriant requiring, on account of the large amoimt of trans- 

 piration at the leaves, much more water than the others. 

 Owing to the height of the house, and the abundance of light 

 and air, the crops were scarcely at all dravm up, and, at the end 

 of the growing season, the crop presented a very natural appear- 

 ance. In each of the forty pots fifteen seeds were sown on the 

 16th May, and nearly every seed germinated. When the braird 

 was 6 inches high the less vigorous plants were plucked out, 

 leaving ten plants in each pot. From the time tluit the plants 

 were 1 inch high until they attained the height of 2 feet, clear 

 drops of liquid, which would be called dew-ih'ops, formed regu- 

 larly on certain parts of the leaves, usually at the ends. These 

 were exudations of the plant, for, when collected and carefully 

 evaporated, there was left Iteliind a residue which, on being 

 examined by the microscope, was found to consist of beautiful 

 crystals. The following table exhibits the results of these experi- 

 ments : — 



