210 EXPERIMENT STATION RECORD. 



process from tlie table given by Archbutt (Allen's Commercial Organic Analysis, 

 4. ed., vol. 2, p. 94), and also for the total volume of 70 per cent alcohol used in 

 precipitating and washing (including the 100 cc. added in the first instance). 



"If there are no crystals from 90 per cent alcohol, or if they are only in very 

 small amount, add a sufficient quantity of water to reduce the strength of the 

 alcohol to 70 per cent (31 cc. water to 100 cc. 90 per cent alcohol). Crystallize 

 at 17 to 19° for an hour, filter, wash with 70 per cent alcohol, and weigh as 

 before, adding the correction for 70 per cent alcohol. If the melting point is 

 below 71°, recrystallize from a small quantity of 90 per cent alcohol, or again 

 from 70 per cent alcohol. 



" The following oils gave no crystals : Olive oils, including ' nice superfine,' 

 'nice seconds,' 'Malaga,' and 8 of unknown origin, almond, poppy, and rape 

 oils." 



A clinical method of estimating- the amount of calcium in the urine and 

 other physiological fluids, W. B. Bell (Bio-chem. Jour., 6. (1912), No. 3, pp. 

 205-209, figs. 2). — Finding that the precipitates obtained with oxalic and acetic 

 acids for many specimens of urine were pure calcium oxalate, providing the 

 proper precautions as regards phosphates were observed, a method was devised 

 for determining the calcium in urine and similar fluids. 



"A sample from a 24 hours' specimen of urine is made faintly acid with 

 hydrochloric acid to dissolve any insoluble phosphate present. It is then made 

 faintly alkaline with ammonia, and filtered. Next 5 cc. of the filtrate is placed 

 with a pipette in the special centrifuge tube, which is of the usual size and 

 shape in the upper portion, but tapers at the lower end into a cylindrical ex- 

 tremity of even bore (1.25 mm.) and calibrated into 1 mm. divisions. A line, 

 with ' urine ' marked below it, encircles the upper part of the tube at the 5 cc. 

 level. Any air bubbles which may collect in the calibrated portion are got rid 

 of with a fine wire or strand of silkworm gut. Then 1 cc. of the reagent, con- 

 sisting of a saturated solution of oxalic acid in a 5 per cent solution of acetic 

 acid, is added. The correct quantity of reagent (1 cc.) is also indicated by a 

 line round the tube, which is marked * reagent.' Finally 2 cc. of alcohol or 

 methylated spirit, as indicated by the line marked * alcohol,' is added, and the 

 contents of the tube are thoroughly mixed by shaking. 



"The second tube is then taken, and 5 cc. of the standard solution (0.05 gm. 

 of calcium phosphate. Ca3(PO02, is dissolved in a little hydrochloric acid. Make 

 alkaline with ammonia and acid with acetic acid. Add 2 gm. of urea to the 

 solution, and dilute the whole up to 100 cc. with distilled water ; specific gravity, 

 1.015) is run into it with a pipette that is up to the line marked ' solution,' and 

 any air bubbles removed as before. Next the reagent and alcohol are added, as 

 in the case of the first tube, and the whole is thoroughly shaken. Both tubes, 

 with their calibrated end packed in wool, are then carefully placed in the oppo- 

 site buckets of a centrifuge, and are centrifuged for about a quarter of an hour. 

 On removing the tubes the precipitate will be found to stand at a certain height, 

 say 10 mm. in the ' standard-solution ' tube, while it may stand at 7 mm. in 

 the other, which contains the urine to be examined. As a rule, there is a slight 

 slant on the surface of the deposit. This can be obviated by stopping the 

 machine at the end of 1 or 2 minutes and turning the tubes through half a 



circle." 



When the method was compared with the usual chemical method for deter- 

 mining calcium it was found that the greatest difference never amounted to 

 more than 1 per cent of the quantity present in the sample. 



A new method for detecting methyl alcohol, P. N. Raikaw (Orig. Commun. 

 8. Internat. Cong. Appl. Chem. [Washington and New YorJc'\, 25 {1912), Sects. 

 I-Ve, pp. 417-419) .—The method is based on the behavior of nitromethan and 



