1919] AGKICULTURAL CHEMISTRY — AGROTECHNY. 615 



ncld have disappeared. After removing the excess water, the agar Is placed 

 on cotton wool filters in funnels resting In filtering tins. These are then auto- 

 claved at 120° C. for one houi-. The agar thus melted, sterilized, and cleaned 

 is an approximately 9 or 10 per cent solution, which on cooling, forms a firm 

 jelly. This is broken up into fine thrieads by passing through a rotary meat 

 grinder. The threads are spread evenly In a thin layer over a number of 

 metal trays, which are placed in a specially designed drying oven and desic- 

 cated at a moderate heat. 



A series of observations made during the manufactui'e of different batches 

 of desiccated agar by the above process is reported, which indicates that the 

 best results are produced by the use of a weak solution of sulphuric acid (0.01 

 per cent). A one per cent solution of agar thus prepared is said to be absolutely 

 firm and suitable for agar slants. 



The process is recommended as furnishing a material which, for ordinary 

 purposes, requires no further filtration, and which, owing to the sterilization 

 during the process of manufacture, does not require subsequent sterilization at 

 high temperatures. 



New apparatus for the desiccation or concentration of liquids at a low 

 temperature, L. Marmiek {Ann. Inst. Pasteur, 32 {1918), No. 4. PP- 145-H9, 

 figs. 2). — The apparatus described and Illustrated in this article consists of an 

 evaporator connected with a vacuum pump and tubular condenser and sur- 

 roimded by an outer jacket through which water at the desired temperature is 

 allowed to circulate. The liquid to be condensed is admitted into the evaporator 

 through a closely fitting funnel communicating with two or more horizontal 

 tubes with perforated outlets, which cause the liquid to be thrown out in a 

 fine spray against the side of the evaporator as the funnel is rotated by means of 

 a pulley or pinion. The funnel Is also provided with paddles, which scrape off 

 the condensed product into the lower part of the evaporator. 



The author states that the apparatus has been used successfully for the con- 

 centration of fresh raisin must and glycerinated serums and for the desic- 

 cation of quantities of milk serum and blood. The temperatures of the water 

 bath for these concentrations and desiccations varied from 36 to 4.5° C, while 

 the temperature within the evaporator was as low as from 20 to 26°. 



A new distilling column for laboratory use and its efficiency, M. H. Robert 

 {Compt. Rend. Acad. Sci. [Paris], 168 {1919), No. 20, pp. 998-1000, flgs. 2).— 

 The apparatus consists of a column of connecting bulbs each partially filled 

 with glass beads and the whole sealed within an outer glass jacket in which a 

 high vacuum can be maintained. This is surmounted by a reflux air condenser 

 of any type that affords a large condensing surface and In which the flow 

 of air can be reeulated. The inner tube of this condenser is connected with 

 the inner tube of a third condenser. This tube is shorter than the surrounding 

 jacket, to which it is fastened at the lower end only. In this tube is suspended 

 a thermometer which, owing to the fact that the outer jacket is closed except 

 for an exit tube at the lower end, records the exact temperature of the con- 

 densed liquid. The distillation Is controlled by regulating the heating of the 

 flask and the current of air in the reflux condenser. 



It is said that by means of this apparatus certain separations may be effected 

 quantitatively in a very short time. 



A study of the lactose, fat, and protein content of women's milk, W. 

 Denis and F. B. Talbot {Amer. Jour. Diseases Children, 18 {1919), No. 2, pp. 

 9S-100). — The experimental work on human milk reported in this paper con- 

 sisted of studies of the composition of milk at different stages of lactation, of 

 milk at the beginning and end of a single nursing, of milk taken practically 



