162 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



compounds, but the work was not completed. The cheese investiga- 

 tions were conducted cooperatively by the chemical and the bac- 

 teriological departments of the station. The chemical study of the 

 cheese-making process was well advanced and the part played by 

 bacterial enzyms in this process was given much attention. Studies 

 on the fermentation of citric acid in milk and its relation to cheese 

 making were reported on during the year in Technical Bulletin 14. 

 It was found that the citric acid amounting to about 0.2 per cent 

 entireh^ disappeared during the cheese-making process, being con- 

 verted into acetic acid and carbon dioxid. 



Under other funds, mainly derived from the State, the station car- 

 ried on numerous lines of work. The chemical department gave con- 

 siderable attention to the study of milk and cheese not directly con- 

 nected with the Adams fund project. In continuation of studies of 

 the chemistry of lime-sulphur mixtures reported in Bulletin 329 of 

 the station, investigations were begun in cooperation with the ento- 

 mologist on the chemistry of mixtures of lime sulphur and lead 

 arsenate. The development of a method for determining the purity 

 of quicklime for spraying was undertaken. The method worked- 

 out for the preparation of lime-sulphur wash has enabled fruit 

 growers to make their own preparations at reduced cost. 



The work of the bacteriological department included the classifi- 

 cation of soil and cheese organisms, a systematic study of cheese flora, 

 and the determination of the germ content of milk from producer 

 to consumer. An inquiry was made regarding the system of payment 

 for milk on the basis of its sanitarj^ quality, and a bulletin was pub- 

 lished on this topic. The study of udder conditions as affecting the 

 germ content of milk was completed during the year, and studies of 

 the soft-rot organisms, which have been in progress for several years, 

 were continued. Attention was also given to the bacterial count of 

 milk as influenced by stable conditions, type of milking pail, and the 

 condition of the milker. 



The 10-year potato spraying experiments carried on by the botan- 

 ical department were completed during the past season. These ex- 

 periments have shown a pronounced profit from the systematic use of 

 Bordeaux mixture and arsenicals 'as a result not only of protection 

 from diseases and insect pests, but of stimulation of growth of the 

 plants. Spraying with lime-sulphur mixtures did not prove so effec- 

 tive as the use of Bordeaux mixture. The main part of studies on 

 currant-cane blight was completed and reported upon during the year 

 in Technical Bulletin 18, but experiments on treatment of the disease 

 were continued. Experiments in spraj^ing with iron sulphate for the 

 destruction of dandelions in lawns, which have been in progress for 

 several years, have so far proven unsuccessful. Tests were made of 



