Tebbuaby 21, 1008] 



SCIENCE 



297 



Illness having followed eating oysters of 

 a decidedly bluish green color, an analysis 

 disclosed the presence of copper to the ex- 

 tent of 0.212 per cent, of the dry substance 

 in one instance. Other tests of fresh and 

 canned oysters on the Kansas market 

 showed copper to be present in every case. 

 Twenty-six samples from various localities 

 were secured directly from the shells, and 

 copper found in every instance, the average 

 amount in the dry substance being 0.059 

 per cent. Copper seems, therefore, to be a 

 normal constituent of oysters, and it is 

 probable that some individuals may be 

 affected by it when present in the larger 

 amounts. 



Influence of Fertilizers upon the Composi- 

 tion of Wheat: Haeey Snydee. 

 Nitrogen, phosphorus, and potassium 

 containing fertilizers, singly and in com- 

 bination, were applied to wheat, and com- 

 plete proximate analyses were made of the 

 crop, and a study was made of the influ- 

 ence of the nitrogenous fertilizers upon the 

 amount and form of the nitrogenous matter 

 in the wheat. Milling and technical tests 

 were also made of the wheat, and bread- 

 making tests of the flour. Over forty 

 samples of wheat were included in the in- 

 vestigation. The results show that an in- 

 crease in nitrogen content of wheat can be 

 secured by the use of nitrogenous fertil- 

 izers, but that the additional nitrogen is 

 not all in the form of gluten proteids, a 

 portion of the nitrogen being in the form 

 of amides, nitrates and allied forms. The 

 influence of the fertilizers upon the com- 

 mercial and bread-making value of the 

 wheat is also briefly discussed. In gen- 

 eral an improvement in the quality of the 

 grain was secured by the use of fertilizers. 



The Detection of Formic Acid in Food 

 Products: A. G. "Woodman and Albert 



L. BURWELL. 



The authors have obtained very satis- 



factory results in detecting formic acid 

 used as a food preservative by means of a 

 method based on the dry distillation of 

 calcium formate. 



The method used may be described 

 briefly as follows: Fifty grams of the 

 sample are mixed with 20 c.c. of 20 per 

 cent, phosphoric acid and distilled by 

 steam. 



To the distillate is added 2 c.c. of 30 

 per cent, acetic acid free from formic acid, 

 and about 20 c.c. of milk of lime (100 

 grams CaO per liter). The solution is 

 evaporated to small bulk over a free flame 

 and then on the water bath to dryness. 



The dry residue is scraped into a test- 

 tube provided with a cork and bent de- 

 livery tube and subjected to dry distilla- 

 tion. After the delivery tube has been 

 allowed to drain, 3 c.c. of standard fuchsin 

 aldehyde reagent is added to the distillate, 

 the mixture allowed to stand exactly five 

 minutes and compared with a standard 

 color. 



The fuchsin-aldehyde reagent is pre- 

 pared by dissolving 0.2 gram rosaniline in 

 10 c.c. of freshly prepared saturated sul- 

 phurous acid and allowing the solution to 

 stand until the red color has entirely dis- 

 appeared and only a light straw tint re- 

 mains. This is diluted with 200 c.c. of 

 distilled water. 



An Electrically Heated Polariscopic Tube: 



B. H. Smith. 



The tube consists of a fairly heavy inner 

 tube of brass or other metal of one half 

 inch inside diameter, the ends of which are 

 threaded and capped as in the case of the 

 usual form of polariscopic tube. An aper- 

 ture, equally distant from either end, is 

 threaded to receive a short wide-mouthed 

 tube at right angles, which admits the 

 thermometer. The latter tube, being re- 

 movable, as is also the binding screw, 

 allows a metallic jacket to slip over and 

 protect the resistance wire. A short 



