1041
NOTE.
HYDROGEN SULPHIDE. (Parts per ~oo,ooo). Days incubated.
Sewage only.
Start
0.00
Sewage +sulphate. 0.00
I
0.04
0.04
2
0 .IO
0 .IO
3 4 7
0.30
0.35
8
0.35
1.20
0.IO
2.50
0.IO
2.50
One or two samples of filter effluents decolorized all of the dyes in four days without the production of hydrogen sulphide or odor, and, on the other hand, one sample showed a considerable development of hydrogen sulphide a n d odor without decolorizing in 7 days. These two or three results were, of course, abnormal a n d simply show t h a t absolute reliance cannot be placed on incubation results obtained by the methyleneblue test; in fact, these studies have shown (I) t h a t the degree of putrescibility of such effluents a s experimented with can probably be better estimated by odor and appearance after incubation than by the time required t o decolorize dyes; (2) the hydrogen sulphide formed comes very largely from albuminous compounds in the effluents and the amount formed is, t o some degree, a measure of the putrescibility of the sample tested; ( 3 ) ' o n the whole, i t would seem t h a t if a putrescibility test of the methylene blue kind is t o be adopted, equally good results can be obtained in a shorter time by the use of indigo carmine or methylene green. I,ABORATORY OF T H E
LAWRENCE EXPERIMENT STATION,
LAWRENCE, MASS.
NOTE. The Quantitative Determinution of Arsenic b y the Gutzeit Methd.-In the issue of Chemical Abstracts for April IO, 1908, p. 976, is a n abstract of a note by T. F. Harvey on the estimation of arsenic by the Gutzeit test. As this immediately follows the abstract of a n article by Sanger and Black on .the quantitative determination of arsenic by the Gutzeit method, the casual reader may be led to infer t h a t Sanger and Black were anticipated by Harvey in the method published by them. I have already called t h e attention of the editor of the Journal of the Society of Chemical Industry t o the misleading nature of Harvey's article, and Mr. Harvey himself has assured me that it is quite clear t o him that his work had not come t o our notice. The Harvey method, however, is merely a quantitative treatment of the ordinary Gutzeit test, while the paper of Sanaer and Black not only introduces a different
principle intls t h e proceclurI., Imt al:m iiiclutlc s ;I d.tai1i.d study of t!ie CILIRLIS KOBI:RTSANGEK. conditions of t h e rcactioii. fIARVhRD
UNIVERSITY. c . A X l ~ K l L J l > M ~ ~A , SS..
April y 1908. . .
NEW BOOKS. Lehrbuch der Gerichtlichen Chemie. 13. In zwei Banden. Zweitc ganzlich urn schweig. F. I'ieiveg und Sohn. 190;.
"i' E I I T
I' s u
V O I ~ ~ I ' L AISI ER .
8'-svi, 490, BrnunSlnrks, bound 13 Marks. age.
The first volume of the new edition of this manual by Dr. Baumert of the University of Halle is devoted t o t h e detection and determination of poisons and noxious substances in t h e catlaver and cxcrctions, in foods and beverages, household articles, imtcr, air ~ ~ i isoil c l and t o chemico-legal problems in general. \'olunic I1 will hc. written by Drs. Dennstedt and Voigtlander, of Hamburg, aiid will lii. confined t o the iiiethods for the examination of inks, writiiigs, signatures, forgeries, etc., aiid t o the cxamination of blood, blood and spermatic stains and materials of a similar nature. Dr. Baumert is entitled t o the thanks aiid gratitude of analysts for having placcd in their hands a manual of legal cheinisir!. truly worthy of the name. Although a hook of oii1)- 490 pagcs, it is a marvel of compactness and thoroughness, .\ reader. glancing ovcr the table of contents, would be a p t t o form t h e opiiiion that tlic treatment, iri general, must be incomplete, elerncntary mid unsatisfactory, h t upon careful study it becomes apparent that this is not t r u e and that ivc. h a w hcrc one of those rare cases where an autliol- has lieen able t o (10 justice t o his subject in remarkably few ir-ords. and t1ut contrary t o thc 1-erhosity of so many German writers we lia\-c i i i this 1)ook a i l exceptionally terse style. While it is evident that the niaiiual Iias I ~ c e nwritten to incet the nceds of German chemists. the discussions arc oi'sucli :t iiaturc. ant1 the reference t o legal points and practice of sucli :I xractvr that it I T ~ ~ be J - consulted with profit by all experts. At ihc pr l i t tiiiie this little book is unique in its ficld. being much niorc' t liaii ;L iiiaiiual oi tlc~termiiiativctosicolog?.. The author confines Iiiiiisclf strictly t o t l i c , cliciriistr!. of thv Inatcrials discussc)d, all qwstions involviiig ph!-siological cffccts, etc., being avoided so far a s possible on the ground that sucli clucstions are not 1c.gitiiiiately those of the chemist but ratlier of tlie medical expert, and that when the chemist has reported that in his judgniciit a sti1)stancc is or is not prcscmt his work is done. A n y suliseyuent questions 3 s t o whether the inatcrial found caused dcath. or could Iia17c causctl tlcntli or \\.as prcscnt contrary to law arc not within the proviiicc ol t!w clic~iiiico-leI:.alexpci-t. The introduction is clc\-otctl lo ii vrry Iiriei stateincwt oi fundamental facts relating to poisons a i i t l norioii.; wljstaiices, much spacc being
