128 THE AMERICAN MONTHLY [July 



solution : Crystalized copper chloride, 2*0 parts ; crystall- 

 ised copper acetate, 2*0 parts ; lactophenol, 95*0 parts ; 

 water containing^ algae is mixed with 10 per cent of the 

 above solution. The whole material is preserved 

 thereby for a long" time. Lactophenol glycerin jelly : 

 White g-elatin, 85; distilled water, 44; g-lycerin, 30; 

 dissolve by heating- on the water bath, filter and mix 

 with 10 parts of lactophenol. Lactophenol copper glycerin 

 jelly : Prepared as above with the substitution of 10 parts 

 of lactophenol copper for lactophenol. Phyocyanin and 

 chlorophyll retain their color excellently in this medium. 

 Lactophenol gum'. A strong- solution of g-um arabic in water 

 1, g-lucose 2, and lactophenol. For preparing- mosses for 

 the herbarium. Potassium mercuric iodide glycerin: The 

 author states that the salt dissolved in concentrated anhy- 

 drous g-lycerin g-ives a mounting- medium of 1*78 to 1*80 

 refraction index. He recommends the mixture for Dia- 

 tomacea3. The preparations are ringed on with amber or 

 dammar varnish mixed with two per cent of boiled linseed 

 oil. — Pharm. Centr., xxxviii., 544. 



Astronomy. — The microscope is useful in astronomy — 

 (1) As applied to the graduated arcs of measuring circles 

 in astronomical instruments of precision, and to the fine 

 divisions on the measuring rods used in determining a 

 base-line, — the fundamental measurement in astronomy. 

 The microscope micrometer, which contains the micros- 

 cope as an essential part, is used extensively ; (2) In the 

 measurement of the position of stars on the Astro-Photo- 

 graphic Chartsand plates obtained by the International Con- 

 gress for their catalogue of all stars of the first eleven mag- 

 nitudes ; (3) In the determination of differential stellar 

 parallax from photographic plates ; (4) In the study and 

 observation of the heavenly bodies as advances in astro- 

 nomical photography make it possible to produce slides of 

 sufficient fineness for the purpose. 



Woods.— L. W.Hahn, Silver Creek, N. Y., offers 110 

 varieties of foreign and native woods for $3.00. 



