314 EXPERIMENT STATION KECOED. 



taiued. " Tlio soluble f:ill.v acids :uv liislicsl immediately after iiarlnrition, 

 or at tbe beginning of the period of lactation. Slight irregularities excepted, 

 they decreased as the period of lactation advanced and were lowest toward 

 the close of the period of lactation." 



Churning tests (12 in number) were conducted in March and May. "In 

 the March butter the percentage increase of the moisture of the soft fats over 

 that of the hard fats was 77.02. In the May butter the percentage increase of the 

 moisture of the soft fats over that of the hard fats was 104.28. These [results] 

 show that the soft fats are capable of taking up a great deal more moisture than 

 the hard fats, [and that] the moisture content of butter made in early summer 

 is due to the increase in the soft fats it contains. 



" The moisture-retaining property of the fats is largely dependent on their 

 melting point. The lower the melting point, the greater is their power to mix 

 with and retain water. Since the glycerids of the oleic and soluble fatty acids 

 have a low melting point, it is reasonable [to assume] any increase in the per- 

 centage of these glycerids tends to increase the water-retaining properties of 

 butter." 



The use of m^etallic containers for edible fats and oils, J. A. Emery ( U. 8. 

 Dept. Agr., Bur. Aniin. Indus. Rpt. 1909, pp. 265-282). — This investigation, 

 which was carried on with vessels and sheets of tin plate, galvanized iron, 

 copper, tin, lead, zinc, aluminum, and iron, was for the purpose of determining 

 the action of fats and oils uix)n metals, with particular reference to the utility 

 of these metals as containers. 



The work shows that where an increase in the acid content of the fat or 

 oil was noted there was an increase in the solvent action of the oil for metals, 

 particularly where other favorable conditions, such as heat, moisture, and 

 exposure to the atmosphere, were pi'esent. With cotton-seed oil, however, an 

 exception was noted, as this oil, when compared with a corn oil of lesser or 

 approximately the same acidity, showed little or no effect uiX)n metals. 



" It [was] demonstrated that zinc, copper, and lead are somewhat readily 

 acted upon, while aluminum, iron, and tin, in the order in which they are 

 named, liave offered evidences of higher resisting power and are the metals 

 which would more satisfactorily meet the requirements of both manufacturer 

 and consumer." 



Chemistry of fumigation with hydrocyanic-acid gas, C. C. McDonnell 

 (C7. -S. Dept. Agr., Bur. Ent. Bui. 90, pt. 3, pp. 91-105, fig. i).— This work con- 

 siders the chemical problems involved in the liberation of hydrocyanic acid 

 from cyanids, and lays special stress upon the action of mineral acids on 

 cyanids and hydrocyanic acid with particular relation to fumigation. 



The residue from the sodium cyanid was found to retain less hydrocyanic 

 acid than the potassium cyanid. A formula recommended as practical for field 

 fumigation work is 3 parts sodium cyanid, 4 parts acid, and 6 parts water, the 

 sodium cyanid being expressed in ounces avoirdupois and the acid and water in 

 fluid ounces. ^ 



The author points out that all mineral acids cause more or less decomiwsition 

 of hydrocyanic acid, but that in the amounts in which sulphuric acid is used 

 for fumigation work the loss from this source may be overlooked. As com- 

 mercial sodium and potassium cyanids contain considerable amounts of sodium 

 chlorid, the author made some tests with mixtures of pure sodium cyanid with 

 from 9 to 66.66 per cent of sodium chlorid. The amount of hydrocyanic acid 

 decomposed varied from 9.62 to 92.09 per cent, and the amount retained in the 

 residue was from 1.4 to 0.63 per cent. One of the principal decomposition 

 products was ammonia, the greater part of which was held in solution in the 



