io2o Annual Registration of Stallions, [march, 



the second season leaves a very much reduced crop, and by the time 

 of the third cutting the number of thistles remaining is small. 



Foreign Experiments. 



Influence of Bacteria on Phosphoric Acid in the Soil (Centralblatt 

 fur Bakt, &>c. II. Abt. Bd. 28, No. 22/24). — These experiments were 

 carried out with a view to ascertain the part played by bacteria in the 

 change of insoluble phosphoric acid into soluble phosphoric acid in the 

 soil. The method followed was to place some well aerated, sifted and 

 sterilised soil in a flask, kept in the dark at a temperature, of 30 0 C, 

 and to inoculate this soil by the introduction of the bacterial culture, the 

 effect of which was to be tested. The sample of soil was aerated by a 

 stream of air from which carbon dioxide (C0 2 ) and ammonia (NH 3 ) 

 had been removed, apparatus being provided to measure the amounts 

 of these two gases in the stream of air after passing through the soil. 

 The energy of the bacteria could be measured by the amounts of these 

 gases, and the effect of the bacteria was determined by comparing the 

 condition of the phosphoric acid in the sample of soil under considera- 

 tion with a sample of soil which was similarly treated except that it 

 was left uninoculated. 



For the purposes of the experiments phosphoric acid was reckoned 

 as soluble when dissolving in 2 per cent, acetic acid. Each portion 

 of soil was kept under treatment for two months. It was found that, 

 far from changing the insoluble form of phosphoric acid into the 

 soluble form, the bacteria played a negative part, since in spite of a 

 rich formation of C0 2 the amount of soluble phosphoric acid in the 

 soil was reduced to an important extent. This decrease is to be 

 ascribed either to the use of soluble phosphoric acid by the bacteria 

 themselves or to a purely chemical reaction. A process was going on 

 during the experiment, however, changing insoluble acid into the 

 soluble form, but it was quantitatively weaker than that opposed to 

 it. The process of C0 2 formation (i.e., the energy of the bacteria) 

 reached its maximum in the first five to ten days of the experiment, 

 a gradual weakening being noticed in the course of two months : the 

 total amount produced in that period was found to be between ten and 

 twenty times greater than in the case of sterile soils. 



OFFICIAL NOTICES AND CIRCULARS. 



The Board of Agriculture and Fisheries are prepared to entertain 

 applications from owners of stallions of any recognised breed for their 

 registration in accordance with the following 

 Regulations for the regulations : — 



Annual Registration 1. Every stallion submitted for registra- 

 of Stallions. tion must have been entered or accepted for 



entry in the stud-book of its breed, viz. : — 

 Thoroughbred stallions in the General Stud-book ; Hunter Sire, Shire, 

 Clydesdale, or those of any other breed in the stud-book of their 

 respective breeds. The owner of the stallion must, if so required, 

 produce to the Board a certificate from the keeper of the stud-book to 



