Ang., I92O.1 U . S . [BUREAU OF MINES NOTES. 269

PHYSIOLOGICAL EFFECTS OF CO.

PLANS are being made to extend work on effects of CO in small quanti t ies Oll men in confined spaces, being conducted by tla.e Bureau at Yale Univers i ty for the New Yo,rk and N e w Jer - sey Sta te Tunne l Commiss ion, to include a general s tudy of effects of CO and associated gases on men work ing in mines and metal- lurgical p,lants.

O I L - S H A L E COMPOSITION.

MICROSCOPIC examina t ion by Dr. R. Thiessen at the Pi t ts- bu rgh labora to ry of the Bureau, of oil shales f r o m Illinois, U tah , Colorado, and Nevada , indicate tha t the oil distilled f r o m the shale is not present in the shale as oil, but as original plant ma t t e r or as degrada t ion products of plants.

A quant i t a t ive me thod for the de te rmina t ion of v i tamine has been devised by ROGER J. WILLIAMS (Journal of Biological Chem- istry, i92o , xlii, 259-265). The method is for the quant i ta t ive de te rmina t ion of the v i tamine which p reven ts beriberi. A syn- thet ic med ium is prepared, each litre of which contains 20 grams cane sugar, 3 grams ammonium sulphate, 2 grams monopotassium phosphate, I. 5 grams asparagine, 0.25 gram calcium chloride, and 0.2 5 gram magnesium sulphate. One hundred c.c. of this meclium is diluted to a volume of I IO c.c., sterilized, inoculated with a suspen- sion of fresh compressed yeas t in sterile wa te r conta ining o.3 mi l l igram of yeas t and hav ing a volume of I c.c. The culture is incubated for eighteen hours at a t empera tu re of 3 °0 C. ; growth is s topped by addition of fo rmaldehyde solut ion; the yeas t is col- lected by fil tration of the culture th rough a weighed Gooch cru- cible, washed with wa te r and with alcohol, dried for two hours at a t empera tu re of lO3 ° C., and finally weighed. This is the control exper iment , and the yield of yeas t is approx ima te ly 2.5 milligrams. At the same time, IOO c.c. of the synthet ic med ium and a definite vo lume of an ex t rac t r epresen t ing a definite weigh t of the sub- stance to be tes ted for v i tamine are mixed, diluted to a vo lume of IiO c.c., sterilized, sown with the yeas t as a l ready described, and then t rea ted in exact ly the same manner as the control experi- ment . The yield of yeas t above tha t in the control is a measure of the v i tamine content of the substance tested. " The ' v i t a m i n e n u m b e r ' of a mater ia l may be defined as the n u m b e r of milli- g r ams of yeas t produced by the addition of its ex t rac t minus tha t produced in a control solution, under given condit ions and within certain limits, computed to I gram of the original material tested."

j . s. H.