1919] AGRICULTURAL CHEMISTRY — AQROTBCHNY. 803 



Bpectora in New York City, April 26, 1919. The terms " renin de milk ami 

 cream" are defined as the "products resulting when skim milk powder or 

 unsweetened condensed milk, sterilized or superheated, are mixed with un- 

 salted butter or with heavy cream, fresh or frozen, and with water, either 

 by means of some crude device such as a bakers' whip or by means of the 

 einulsitier, viscolizer, or homogonizer ; or when whole milk powder, preferably 

 made from homogenized milk, is mixed with water by means of such a device 

 as a baker's whip or in a mixing tank equipped with a revolving propeller or 

 paddle." 



The advantages claimed by the manufacturers for the use of these products 

 are stated, the report of Coutts and others, on dried milk powder (10. S. R., 40, 

 p. 379) is summarized and discussed, and four methods developed at the Bureau 

 of Chemistry which are said to differentiate quantitatively the natural and re- 

 made products are outlined. One of these methods depends upon the migra- 

 tion or transference of the protein molecules under the influence of the electric 

 current; the second, upon the relation of the viscosity to the total solids and 

 solids-not-fat; the third, upon the amount of fat left in the skim milk after 

 centrifuging; and the fourth, upon nephelometric readings on the sterijized 

 remade product after inoculation with peptonizing bacteria and Incubation. 



In conclusion the author indicates methods which should be adopted for con- 

 trolling these products. 



Chemical constants of avocado oil, F. W. Albbo (Ann. Rpt. Cal. Avocado 

 Assoc, 1917, pp. 92, 93). — Avocado oil was obtained from fresh pulp by extrac- 

 tion with petroleum ether and from dried pulp by extraction with low-boiling 

 gasoline, filtration through animal charcoal, removal of the solvent by means 

 of carbon dioxid, and decantation after cooling to 5° C. The chemical con- 

 stants of the latter oil were as follows: 



Iodin number 85 to 8S, Hehner number 92.5, acid value (free oleic acid) 

 4 to 6, Maumenc number 65, specific temperature number 156 to 157, average 

 molecular weight of fatty acids 282.2, saponification number 177 to 178, 

 Keichert-Meissl number 3.8 to 4, Polenske number 0, acetyl value (real) 11.3, 

 refractive index of oil at 15.6° 1.47, refractive index of fatty acids ;it 40° 

 1.454, and oleic acid 80.S5 per cent. Similar results were obtained in the 

 determination of some of the constants of the oil from fresh pulp, the most 

 marked difference being a higher acid value as free oleic acid (8 to 12). 



Oil from Mgongo nuts (So. African Jour. Indus., 1 (1918), No. Ik, pp. 1885, 

 1286). — Mgongo nuts grow principally in the Livingstone District of northern 

 Rhodesin, and are said to be identical with the Manketti nuts of southwest 

 Africa. From analyses of two samples of these nuts at the Imperial Institute, 

 it was found that the true kernels with the seed removed yielded 58.1 per 

 cent of oil. The possibility of utiliizng the nuts as a commercial source of 

 oil depends primarily on the practicability of extracting the seeds from the 

 tough and extremely hard outer shell. Whether this could l>e successfully 

 done on a commercial scale seems, in the opinion of the Institute, doubtful. 



Contribution to the study of the oils and press cake obtained from the 

 seeds of raisins, currants, and tomatoes, EtOTHXA (BuL Sci. I'hnrtnnrol.. 26 

 (1919), No. 3, pp. 105-110). — This article contains data on the moisture and fat 

 content of the seeds of raisins, currants, tomatoes, oranges, and melons; 

 analytical constants of the pressed oils; and proximate analyses of the result- 

 ing press cakes. 



The oils are said to be of an agreeable odor and flavor with the exception 

 of currant seed oil which, on account of the presence in the seeds of a lipo- 

 diastase, has too high an acid content to be edible. The press cakes from 



