CARBON DIOXIDE A S A MEASURE OF THE EFFICIENCY OF VENTILATION.'

B\- E L I . F N 11. R I C I I . \ K I ) S , 1 T S I ' K I C T I ) K I S 5 \ S I I ' A K \ i'l?l:>lIbl'ki' ?tI.lSX.\CHCSI:TTX IS STITL'I'I09 1)1' TF.CI~NOI.O(:S. k ) \ T O S . hq.1S.i

ROM the time of Hippocrates who gave as tlie sanitary F riiaxirn "pure air, pure water and pure soil," air has been placed first among the requirements of good sanitation. I t is nevertheless a lamentable fact that, as Mr. LVoodbridge has well expressed it, " the city which speiids millions i i i water works for pure water supply and for sewerage for foul water removal. is still found tightening its pnrse strings wlieii a few thousands are asked for to provide for pure air supply to, a i d foul air dis- charge from its school roonis."

The reason of this apathy is riot far to seek. Chemists and sanitarians have seriously disagreed anioiig themselves a5 to what constituted ' ' had air. ' '

People live and apparently thrive among the most nauseous odors. while under more favorable conditions they sicken and die. One theorist has givcii a reason only to be forced to the wall bj, another quite as plausible. Between them the ad\Tocate of pure air finds slight hearing. It is o111y withiii recent years that a knowledge of the significant fact that not to air itself nor even to tlie bad odors it carries, but to tlie dust particles bear- ing living germs and spores is to be attributed the spread of dis- ease, therefore filtered air like filtered water has becoine a neces- sit). where dust cannot be avoided by scrupulous care.

Xiid ti(j\v with our increased kiiowledge of tlic causes which lead to liability to disease it seems probable that tlie cheiiiist and sanitarian may at 1xst unite i n R winni,ig fight for pure air. 111 R word, the new staiidpoiiit relates to t!ie resis tarm which healthy blood nuti tissue piesent to tlie attacks of disease. This resistance is, we believe, due to the perfect nutrition of the blood corpuscles and this is largelj. depeiident oti the in- halation of air containing sufficient oxygen.

In vitiated air the blood becomes quickly loaded with iiiiper- fectly oxidized products which cause derangenient niore or less serious arid filially render the individual, wlio is poisoned frorii

1 Abstract of a paper rend before tlir World's Coilpress of Chrnii.ts. August 26, I&J.

CARBON DIOXIDE AS A MEASURE, ETC. 5 73

utthin rather than front without, more liable to succumb to disease

If this view is in any measure correct it is important that chemists combine to urge upon the community the importance of a sufficient supply of air, especially in school rooms, and it is to be hoped that these views will command more respect than heretofore. I t is notorious that even college halls and fine public buildings which should be examples, are in fact the worst of any buildings.

The Laboratory of Sanitary Chemistry at the Massachusetts Institute of Technology has had, for the past nine years, ex- ceptional opportunities for the study of the relation of the amount of carbon dioxide to the efficiency of the ventilation, in that the Walker building is supplied with mechanical ventila- tion under the direction of an expert and in full control of the engineer who has records for all these years of the arnount and temperature of air supplied to eazh room, and of the tempera- ture of these rooms taken four times each day.

During these nine years some 5000 determinations of the amount of carbon dioxide have been made in these rooms by some zoo students.

Many problems have been studied and several reports pub- lished; without burdening this paper with details, to state a few of the conclusions reached may stiriiulate others to add to our too meagre knowledge on this subject.'

The outside air of the space around the Massachusetts Insti- tute of Technology, Boston, varies from 3.7 to 4.2 parts carbon dioxide per 10,000.

The deterioration of the air as shown in the empty rooms is 1 Papers relatiiig to the poiuts discussed, coiitributed iu whole or iu part from the

Laboratory of Sanitary Chemistry : "On the Determiuatiou of Organic Matter in Air." Thei i i , by Marion Talbot. Ted-

no1ox.v Quarter@, I , 1887-8. "The Nuinber and Distribution of Micro-orgauiuins ill the Air of the Bostou City

Hospital with some Carbon Dioxide Deteriniuatioiis." By Greerileaf X. Tucker iu the tweutieth an:iual report of the State Board of Health. of Massachusetts.

" A Critical Study of the Heating and Ventilatioii of the Walker buildiirg, Massachu- setts Institute of Technology" By S . H. Woodbridge. Ttch,rolug.v ~ ) u u r t d y , 2, p. 76 and 192, rSS8+.

By A. H . Gill.Jour~rra1 o/ Analyfical aud Applied Chemist<v, 6, 2892. This paper gives the inethod in detail which is used iu the laboratory.

"The Deteriniuation of Carbon Dioxide in the Air of Buildiiigd."

574 ISTERNATIOS.ZI , I N D E X TO CHEXIC. \ I , I , ITl<R.iTI-RT<.

about 0 . j part, due to tlie deconil,ositioii of the o r p n i c matter present in the flues. the floors aiii1 i i i t?ic \ ~ a l I s .

The a i r of tlie building i n general> Iialls : ~ i i d tira.iviiig rooiiis, reading rooiiis. etc., u.11ich a:-? open anti i i i \vliicli people arc- constaiitiy moving, is iiiaiii!aiiietl a t :ibout ,s .o part:: as an a\ .cr- age of examinations during eig-lit yc-ars. In tlie riiiitli year t1iei.c has heeii 3.11 iiicrease tliie to xi1 iiicrrasetl iiiiiiii;i:r of lerturt- rooiiis oil tlie second floor.

Tlie air of iiiost of the lecture I-ooiiic; iias coiitaiiictl from six to eight par ts , of tlie 1arg:cr croivded lialls for zoo or iiioi'e students. ten to twelve parts nccorditig to ivcatlier. n-lietlier i t is clear ant1 dr!, a i i c t ivitli n stroiig wiiiti. or svlietlier the air is loatlctl with moisture and is still.

I=roiii this esperieiice it \voultl sc'eiii tliat stutieiits caii ivork \\-ell iii n clc:tii room \vitli a1)out seven parts 1 x 1 1 0 . 0 0 0 of c2rh;ii tliosirlc : !iiuch iiiorc tlinri tliis cnustrs t lu l l i i es~ , :tiid aiiytliiiix CI\W tliirtwii p;irts t~iiises i l l most cnseb nii nliiirist itiip barrier to tlie iull acqiiisitioii of kno\vletlge.

IYlieii churches, 1iai1s, aiid lwtui-e roniiis usual1~- show fro111

fourteeii to cigliteeii 1Jaytq p r ro,cioo i i i tweiit! iiiiiiutes after tlie xuclieiicc as~c;ii l) lcs, it i s iiot stc:iiixe tli:it cioqueiice oftell fa i 1 s to nro 11 :;e e i i t 11 usi :is11 1.

AN INTERNATIONAL INDEX TO CHEil lCAL LITERATURE.'

UKIXG o m of iiiy 11il.iliographical tours i n ICiirope, ai1 enii- D iierit librarian of a German University remarked : ' ' You Americans are doing more and better work iii bibliography than all tlie nations of Europe takeii together." And this lie said iiot in flatter)- but as the espi-essioli of an earnest conviction. Later I expressed surprise that Gernians with such splendid col- lections of books and other adrxntages should leal-e it to Aiiieri- cans to cross the Atlantic and wrest from Europe inaterials for general aiitl special bibliographies. To this lie proiiipt,ly re- plied : ' ' Acli nieiti Freund, das Geld fehlt ! "

I shall iiot attempt to demolistrate the accuracy of the gentle- man's statements, as it would involve coniparisons, and these

l i s t i . C ' A n K I X , . r o s 1k~r:roS.

1Kead before the \Vorld's Coiigress of C h e u i s t s . Ailgust 23, xSsj