December 18, 1896.] 



SCIENCE. 



913 



Anthropology (Vol. IV.), Prof. L. Moschen 

 discusses the craniology of the Umbrians. 

 Previous writers (Nicolucci, Calori, etc.) 

 have asserted that the ancient Umbrians 

 were slightly dolicocephalous or mixed. 

 Moschen claims that there are no undoubted 

 skulls of pure blood Umbrians of antiquity, 

 and therefore that these older studies are 

 of little or no value. He undertakes to 

 study the true modern type, following the 

 general terminology of Sergi. They pre- 

 sent a large variety of skull forms, with a 

 prevailing tendency to mesocephaly and 

 leptorhiny. He divides his series into eight 

 principal varieties or forms, the ovoids and 

 ellipsoids predominating. 



It is difficult to draw any racial conclu- 

 sions from this study. 



D, C. Beinton. 



Univeesity of Pennsylvania. 



NOTES ON INORGANIC CHEMISTRY. 

 The question of impurities in atmospheric 

 air is one that has been investigated by 

 many chemists and from many standpoints, 

 and one upon which much light has been 

 thrown in recent years. One of the most 

 important phases of this subject cannot be 

 said to have yefc approached a solution. 

 That air in crowded rooms, and especially 

 exhaled air, is poisonous is well known. 

 The ' black hole of Calcutta' is but an ex- 

 treme case of what we have all many times 

 experienced in poorly ventilated audience 

 rooms. These evil effects were early attrib- 

 uted to an excess of carbon dioxid, which 

 was certainly present. "When it was shown 

 that carbon dioxid of itself is not a poison, 

 a certain mysterious ' efHuvium ' in exhaled 

 air was conjured up, but its nature eluded 

 investigation. The reduced proportion of 

 oxygen has also been considered a cause. 

 !N"one of these explanations, however, can 

 be considered satisfactory. That the un- 

 pleasant effects of crowded rooms could be 

 due to nitrites in the air has also been sug- 



gested, but never sufficiently investigated 

 to give a satisfactory answer. A contribu- 

 tion to this phase of the subject has been 

 made by Mr. George Defren at the Massa- 

 chusetts Institute of Technology, and pub- 

 lished in the Technological Quarterly (9: 238). 

 His work was mainly confined to the de- 

 termination of the quantity of nitrous acid 

 (or nitrites) in the excellently ventilated 

 rooms of the Institute Laboratory. After 

 a brief summary of the work of previous 

 investigators, Mr. Defren gives an account 

 of his own experiments. 



The method first used was to expose pure 

 water in porcelain dishes for from one to 

 nineteen hours, and then estimate the ni- 

 trites absorbed by Griess' reagent. In 

 every case nitrates were found. The quan- 

 tity was dependent on the time the water 

 was exposed, and on the nature of the 

 work being carried on in the room. The 

 burning of illuminating gas seemed to oc- 

 casion the formation of nitrites ; whether 

 this is due solely to the incomplete oxida- 

 tion of the nitrogenous constituents of the 

 gas, as Mr. Defren believes, or to a direct 

 union of the nitrogen and oxygen of the 

 air, may be an open question. The second 

 method used was quantitative and consisted 

 in drawing air into large bottles, adding 

 water and analyzing after twelve or more 

 hours. The amount found was small on 

 clear days (as low as .014 part nitrous anhy- 

 drid in 10,000 parts air), but was increased 

 by the burning of gas and the presence of 

 the people in the rooms. The largest 

 amount found was .07 pai'ts in 10,000. Ex- 

 haled air was tested by blowing through 

 water, but no trace of nitrites was found, 

 contrary to expectation. Mr. Defren sug- 

 gests that nitrites present would, by the 

 large volume of oxygen present, be oxidized 

 to nitrites, or even decomposed to nitrogen. 

 A test showed that even air containing 

 nitrites, when drawn through water, gave 

 no reaction. On the other hand, water in 



