and Laboratory Methods. 2489 



To convert drams into grams, multiply the number of drams by 3.75, and to 

 convert grams into drams divide the number by 3.75, or less approximately and 

 more conveniently by 4. The same rule is to be observed in dealing with 

 ounces. But in converting mimims, as observed in the second table, into the 

 metric system the number of minims must be multiplied by .061 c. c, the num- 

 ber of fluid drams must be multiplied by 3.75 c. c, and the number of ounces 

 by 30 c. c. R. p. 



... ^ . n ^ t ^, Ij^ making pieces of apparatus for 



Waterproof Cement for Glass. , .... 



experimental work, m repairing or 



remodeling aquaria and for various laboratory practices it is frequently desir- 

 able to have a cement which will hold pieces of glass together firmly, and at the 

 same time will not be affected by water. The Scientific American (February 

 28, 1903) gives some useful formulae for such cements. These are : 



1. Dissolve 5 to 10 parts gelatine in 100 parts water; add 10 per cent, of 

 a concentrated solution of bichromate of potash, mix thoroughly and keep in a 

 dark place. When the articles joined by this cement are exposed to sunlight for 

 a short time, the cement becomes tough and insoluble in water. 



2. Quicklime . . . . . 4 parts 

 Litharge . . . . . " 

 Linseed oil varnish - - - . l part 



R. p. 



c,j. . . . n A' * II . c^ J. Kozlowski (Das Conserviren und Fai- 



StaioiDg and Preservation of Urine Sedi= .... 



ujgujg ben von mikroskopischen Priiparaten 



der Harnsedimente. Virchow's Arch. 



169: 161) centrifugates the urine with about one-tenth part (volume) of a 1 per 



cent, eosin solution. After separation of the fluid a drop of the sediment is 



mixed on a slide with a drop of Farrant's medium (water, glycerine and a cold 



saturated solution of arsenious acid in equal parts, to which is added as much 



gum arable as will dissolve) and covered with a cover-glass. The mounts should 



be sealed with some good cement. Preparations so made will hold the stain 



and not undergo any essential change for at least five years. R. p. 



QUESTION BOX. 



Inquiries will be printed in this department from any inquirer. 

 The replies will appear as received. 



No. 31. — Will some one give a description of a small aquarium for a private 

 laboratory to secure specimens for demonstration in high schools, etc., and the best 

 method to sustain life by isolation of species, gravel or mould aeration by water, 

 etc., etc.? B. E, B. 



No. 32. — What is the best food or manner of treating biology specimens to 

 keep them alive, as used in Huxley & Martin's Biology ? b. e. b. 



