AGRICULTUEAL CHEMISTRY AGROTECHNY. 203 



Oils of the Coniferae. — II, The leaf and twig, and bark oils of white fir, 

 A. W. ScHORGEB {Jour. Indus. andEngin. Chem., 6 (1914), No. 10, pp. 809, 810).— 

 This continues previous work (E. S. R., 33, p. 18). 



The approximate composition of the oils of white fir (Abies concolor) is 

 given as follows : ^a-piueue 12 in leaf and twig oil and 9 per cent in bark oil ; 

 Z-B-piuene 42 and 60 per cent ; ester as bornyl acetate 6.5 and 2.5 per cent ; free 

 borneol 9.5 and 4.5 per cent ; and " green oil " 3 and 5 per cent, respectively. 

 The leaf and twig oil fraction boiling at 170 to 180° C. showed 15 per cent Z-phel- 

 landrene, while the bark oil fraction at the same temperature showed dipentene 

 12 to 13 per cent. Furfurol was present only iu traces in the leaf and twig 

 and in the bark oils, and Z-camphene was noted only in the leaf and twig oil. 

 The material unaccounted for in the leaf and twig oil was 4 per cent, and iu 

 the bark oil 7 per cent. 



Milk — its milk sugar, conductivity, and depression of freezing point, 

 LiLiAs C. Jackson and A. C. H. Rothera (Biochein. Jour., 8 {1914), No. 1, pp. 

 1-21). — In this paper the results of measurements of the electrical conductivity, 

 percentage of milk sugar, and depression of the freezing point are reported as 

 a basis for drawing certain physiological deductions and interpretations rather 

 than as a means for the identification and characterization of different milks. 



" In milks secreted from different quarters of the cow's udder and from the 

 right and left breasts in women the electrical conductivity and percentage of 

 milk sugar show a strict reciprocity, provided that the secretion of the milk 

 samples corresponds to the same period. In this case the milk samples are 

 secreted against the osmotic pressure of the blood with its variation over that 

 period. They will all have the same osmotic pressure, and if iu one sample the 

 sugar is higher than in another then the electrical conductivity will be lower. 

 The reciprocity of milk-sugar content and electrical conductivity is well seen 

 in the milks from a pathological gland which is slowly recovering and becoming 

 normal. In a comparison of the milks of different species of animals the 

 reciprocity between milk sugar and electrical conductivity is evident. 



" It is shown that the milk secreted under the stimulus of removal (milking 

 or natural suckling) differs in character from that secreted previously. The 

 contention is that the condition of the blood has not kept absolutely constant 

 and that the reflex milk is secreted against a slightly different blood from 

 that against which the previously formed milk was secreted. 



"Morning and evening samples of cows' milk have been compared. The 

 evening milk generally has the higher conductivity, but exceptions exist. 



" The exact effect of the proteins of cows' milk in diminishing the electrical 

 conductivity has been estimated, the value found being a diminution of 2.76 

 per cent of the conductivity for every 1 per cent of protein in the milk. The 

 dialysis experiments employed for determining this effect showed no difference 

 between raw fresh milk and the same boiled for one hour. Also, there was no 

 evidence that boiling has any effect on soluble calcium salts in a state of 

 ionization. 



" The effect of climatic changes upon a Holstein herd of cows has been 

 studied. The generalization holds that hot, dry weather increases the electrical 

 conductivity of the milk, whilst wet or cold weather diminishes it. The 

 climatic conditions affect the cows and so indirectly their milk." 



On the phosphorus content of starch, A. W. Thomas (Biochem. Bui., 3 

 {1914), Nos. 11-12, pp. 4OS-4O6). — Positive experiments confirm the conclusions 

 of Ford "■ and Fouard * that it is impossible to free starch entirely of phosphorus. 



"Jour. Soc. Chem. Indus., 23 (1904), No. 8, pp. 414-422. 



"Compt. Rend. Acad. Sci. [Paris], 144 (1907), No. 9, pp. 501-503. 



