174 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



1. Carbonate of lead, 1/2 oz. ; red oxide of lead, 1/2 oz. : litharge, 

 1^ oz. Grind thor^iighly together in a mortar. Stir some of this 

 into enough gold size to make it work stiffly. If too much adheres to 

 the work, turn it off on turntable when a little set. 



2. Best quality gum arable, dissolve in cider vinegar; add a 

 little sugar. A very strong cement, but not tested for durability. 



Test for Preservative Fluids.* — Dr. C. 0. Whitman considers 

 that one of the best objects for testing methods is found in Phronima 

 sedentaria. Here the cells and nuclei are so sharply defined that they 

 can be seen in the living animal, and so the effect of a preservative 

 fluid can be easily studied. 



Molybdic Acid Test for Protoplasm.t — If a section of some 

 living endosperm is treated with a solution of molybdic acid in strong 

 sulphuric acid, the cell-wall will swell up, and the threads which 

 traverse it will soon assume a blue colour, while the main mass of 

 protoplasm becomes intensely blue. The cell-wall itself remains 

 uncoloured. This very delicate reaction demonstrates the protoplasmic 

 nature of the threads. 



Butter and Fats.| — Dr. T. Taylor in a further paper on this 

 subject, in which he repeats the results already recorded, § says that 

 he has examined a number of other fats, vegetable and animal, and 

 finds thus far, that animals and vegetables of distinctly different 

 genera and even species, yield fats which give typical fatty crystals 

 characteristic of the animals and plants which yield them, and he is 

 confident that this new discovery will prove highly useful to micro- 

 scopists and chemists, when investigating adulterated substances used 

 as food or in medical preparations. 



Micro-organisms in Potable Water. || — Dr. T. Leone's researches 

 tend to show that water which contains carbonic acid is detrimental 

 to the existence of micro-organisms. His experiments were made 

 with a typically pure potable water (Maugfall of Munich), in order 

 to ascertain the number of micro-organisms which could be developed 

 in a given time. 



After repeated examinations it was found that on the fifth day 

 this water contained more than half a million of micro-organisms to 

 every cubic centimetre. It was further demonstrated that there was 

 no practical difference between the number of micro-organisms de- 

 veloped in water kept at rest, or constantly agitated for a given 

 period of time. 



When, however, carbonic acid gas was passed for a period of half 

 an hour through flasks filled with this Maugfall water, the number of 



* ' Methods in Microscopical Anatomy and Embryology,' 1885, p. 16. 



t Ibid., p. 212. 



X The Microscope, v. (1885) pp. 212-4 (8 figs.). Of. also Amer. Men. Micr. 

 Journ., vi. (1885) pp. 163-4 (8 figs.). 



§ See this Journal, v. (1885) p. 918. 



II Atti K. Accad. Lincei — Kond., i. (1885) pp. 726-32. Of. transl. in Chem. 

 News, lii. (1885) pp. 275-6. 



