330 KiRKwooD AND GiES : Chemical Studies 



On evaporation to a small volume on a water-bath the fresh 

 milk becomes darker in color, takes on an odor characteristic of 

 sugar syrups and looks not unlike molasses. Cane-sugar crystal- 

 lizes from it in abundance on cooling. 



The analytic data given on page 329 were obtained in our 

 study of the general composition of the perfectly fresh milk of the 

 Jamaican nuts.* 



Percentage results in this connection had been obtained pre- 

 viously as follows : 



These results were obtained with milk from nuts grown in the 

 eastern hemisphere. The milk from the Jamaican nuts appears, as 

 we have seen, to contain less solid matter, both organic and inor- 

 ganic. This difference is emphasized by Hammerbacher's T[ ob- 

 servations on the specific gravity of cocoa-milk. He describes the 

 milk as a colorless, slightly opalescent fluid with a specific gravity 

 at 20° C. of 1044.** The milk from two nuts weighed 303.95 

 grams. From the nitrogen-free extractive substance in 77.8 grams 

 of milk contained in a third nut, 0.8504 gram of dextrose was ob- 

 tained. When milk was warmed with dilute sulphuric acid an odor 

 of volatile fatty acid became perceptible. A crystalline barium salt 

 was prepared from the distillate of the acidified milk which was found 

 to consist of barium propionate. 



The milk contains a small amount of diastatic ferment and also 

 oxidase.ft We were unable to detect any other enzymes. 



The following results were obtained by van Slyke;|;| in his com- 

 parative studies of the milk of six unripe nuts and of one ripe one : 



* The methods of analysis used for this and similar purposes, throughout our 

 work, were those commonly employed in the laboratory. See Vandegrift and Gies : 

 American Journal of Physiology, 5 : 287. 1901. 



■\ Hammerbacher : Landwirtschaftlichen Versuchs-Stationen, etc., 18 : 472. 1875. 



J Konig : Menschlichen Nahrungs- und Genussmittel, etc., 2: 308. 1893. See 

 also Bizio : Pharmaceutisches Centralblatt, 756. 1833. 



§ Including 4.42 per cent of cane-sugar. See page 328. 



\ Hammerbacher, loc. cii. 



** See our large number of determinations of specific gravity on page 327. Also 

 references on pages 328 and 329. 



•ft Hunger: Journal of the Society of Chemical Industry, 20 : 1030. 1 901. 



JJ Van Slyke : Chemisches Centralblatt, i: 595. 1891. Compare with results on 

 page 329. 



