THE JOURNAL OF PHARMACOLOGY. 



substances. A culture-medium of 0.5 

 per cent, egg albumin or peptone, with 

 1-10 per cent, potassium phosphate, 2-10 

 per cent, magnesium sulphate, and a 

 trace of calcium chloride, was infected 

 with the bacteria of decay, and after 

 addition of the substance to be tested, 

 placed for several days in an incubator. 

 Among inorganic compounds silver ni- 

 trate and mercuric chloride have about 

 the same value, 0.002 per cent., killing 

 all organisms in two days. The anti- 

 septic limit with silver nitrate is 0.0002 

 per cent.; with mercuric chloride 0.00 1 

 to 0.0002 per cent. Copper sulphate is 

 nearly as active, 0.005 P er cent, killing 

 all organisms in twenty-tour hours, and 

 0.001 per cent, preventing decomposition. 

 Zinc sulphate o. 01 per cent, kills irnfu- 

 soria in eighteen hours, but o, 1 per cent, 

 is not completely antiseptic, while cad- 

 mium sulphate toward algae and infusoria 

 is weaker than the zinc salt, but toward 

 bacteria stronger, 0.02 per cent, being 

 antiseptic. Lead acetate and nitrate in 

 o. 1 per cent, solution only delay decay, 

 while the latter is prevented by the same 

 strength of iron sulphate solution. The 

 fluorids are not strong antiseptics, the 

 limits being for hydrofluoric acid 0.02 

 percent., barium fluoride 0.3 per cent., 

 aluminum fluoride 0.1 percent., calcium 

 fluoride 0.03 per cent., ferric fluoride 0.06 

 per cent., and magnesium fluoride 0.05 

 per cent. Ammonium fluoride 0.1 per 

 cent, is without action, but sodium flu- 

 oride o. 1 per cent, is antiseptic; potas- 

 sium fluoride is rather more active. 



Dika Fat. — Odila or dika fat is a vege- 

 table fat, rather extensively used by the 

 natives of the Cameroons district for culi- 

 nary purposes. It is manufactured from the 

 fruit of the wild native mango. It is 

 somewhat darker in color than palm oil, 



though of the same consistency. Plan- 

 tains cooked with dika fat are described 

 as delicious, and indeed the flavor of the 

 fat is most agreeable in the various ways 

 in which it is used in the kitchen. Oils 

 and fats are obtainable in great abund- 

 ance in Western Africa, a large number 

 of fruits, nuts and other vegetable pro- 

 duce supplying them by easy processes. 



Delicacy of Marine's Reagent. — 



Verven reports experiments to deter- 

 mine the delicacy of Marme's reagent for 

 alkaloids (which consists of 5 grams of 

 cadmium iodide and 10 grams of potas- 

 sium iodide in water to make 100 c. c.) 

 The suspected solution is acidified -with 

 sulphuric acid and one-fifth its volume 

 of reagent added. Pecipitation occurred 

 with atropine, 1 in 1,600; cocaine hydro- 

 chlorate, 1 in 16,900 ; veratine, 1 in 

 5,400; strychnine, 1 in 19,200; brucine, 

 1 in 14,600; quinine, 1 in 32,300; con- 

 chinine, 1 in 18,400, and aconitine, 1 in 

 13,7 00. 



Formation of Diastase. — Prof. W. 

 Pfeffer has carried out a series of 

 experiments for the purpose of deter- 

 mining the conditions under which dias- 

 tase is formed in plants. The plants 

 operated on were Penicillium glaucum, 

 Aspergillus niger, and Bacillus megath- 

 erium. An increase in the amount of 

 sugar in the nutrient material was found 

 always to have the effect of decreasing 

 the production of diastase, but the same 

 result was not produced when the sugar 

 was replaced by some other carbohy- 

 drate, by glycerin, or by tartaric acid. 

 Prof. Pfeffer regards the arrest in the 

 production of diastase as not a purely 

 chemical or physical phenomenon, but as 

 one of irritation exerted on the organism 

 by a solution of sugar of a definite degree 

 of concentration. 



