The gencrnl probletn of preetlicting package perforrnnttcc cnn be illustrnted by the following example. The itnngiunry ninterial to be pncked is a wheat product which when pncketl ltas 10% moisture, and which begins to mildew a t 17%. The packets nre to be stored in nn ntniospltere of 96% 1Z.H. The niirtcrinl bulks 50 Ib. to thc bushel, nud is to be packed in pounds (413 g. oven-dry weight). 1 Ib. of the ninterinl would occupy about 530 c.c., so that n conveniently sized piickct would be 9 x 9 x 9 cui. I n calculnting the overall pcrnienbility of any pnckngc it is desirnble to niensiire X, Y, and Z for the niaterinls to IN used, under the conditions which are expected. ~Vlien the niensurenients nrc applied, however, to estimnte the side shelf-life of the pnckngc, n rensonahle safety factor must be uged to nllow for vnrintions ; so if it is not possible to innkc thc niensurcnients, nn upproxintntc rnluc may be ol)tained by using the results quoted above. I t is consitlcred thnt unclcr nonnnl conditions-no clraught, niotleriite tempcrnturc, humidities not cstreme-this \voiild incorporate n snfety fnctor of nl)out ten.If the pncknge is ntntle froin nioisturcproof cellulose filni, by Iientscnling, in tlie form of n 9-ciu. cube, the totnl area will be 6 x 0.092 or 0*0#36 sq. ni. Tlie heat-scnls will be in strips 6 nini. wide, aud the length niny be tnken as that of four sides of the packet, so thnt tlic nrea inodificd by heat-senling (p) is 4 x 0.09 x 0.006 or 0.00216 sq. in. Then by diffcrcncc the uiiultered men, a, is 041614 sq. ni. The length of the folds (8) is tltnt of 12 edges, or 1.08 nictres. From the rnlucs of Y and Z given nlrovc, S = 0.2, Y = 9 . 5 , and dey/nim. If the packet hnd beeu made from siiuilar film, but sealed with nn aillicsire seal 5 nitti. {ride, uitd inensuring 18 x 10 x 8 ctii., it can be estimntcd thnt 1' = 0.0097 + 0.0133 4-0.0017 = 0.0245 g./dny/ntni. KO figures nrc nrnilable yet for other wrnppiitgs, but if it isassumed that tlie overnll pernieal)ility is proportioual to the permeability of the plain wrapping, P for a 9-c1n. cubical packet made from waxed glnssinc would be 0.223 g./tlay/nini. Thc nbovu figures include n lprge safcty factor, but they itre 1111 calculated for cotuplctc exposure. In prncticc the packets would be stacked togctlier, nnd even the most exposed oncs-those at the corners-would only * This work WUII uridurhkcn ut tho mqocst of Dr. J. C. Drummotid, BcientMoAdviaor to tho Ministry of Food.
SURAMIN-PROTEIN COMPLEXES. 231 for optimum precipitation depending on the relative amounts of the drug and the protein. Repeated precipitation by acid followed by solution at pH 7-5 does not reduce the suramin content of the precipitated complexes. 3. Considerable amounts of suramin become firmly attached to proteins such as the serum proteins and crystalline egg albumin at pH 7-5, but much more is bound by the protein in acid solutions, particularly at pH's below 6. 4. The absence of suramin from the red cells of animals injected with the drug is due to the inability of the drug to pass through the cell membrane. Suramin readily combines with the proteins of haemolysed red cells. 5. Suramin injected intravenously as a complex with rabbit serum proteins, or with egg albumin, is not retained longer in the blood than is the injected free drug. 6. The blocking of the free amino groups of proteins by the action of di-2-chloroethylsulphone does not reduce the capacity of the proteins to combine with suramiin. 7. Suramin does not react with the thiol groups of cysteine or proteins. The authors are pleased to express their indebtedness to the Medical Research Council for grants which have partly defrayed the cost of this investigation. We are also grateful to Miss H. M. Dewey for help with one of the experiments described in this paper.
1x7 which had to be taken was to discontinue the addition of bromine if, for some reason or other, the stirrer failed to work. (Accumulation of free bromine in the vessel is dangerous as it might react suddenly with great violence,)The mixture of sulphuric acid and hydrobromic acids was converted into calcium bromide by neutralisation with slaked lime.The solution of calcium bromide obtained was evaporated until a concentration of about 75y0 was reached. Such a solution solidifies on cooling. A typical analysis of the final product was as follows :CaBr, 76y0b.w. ; CaO 0.039y0 ; Fe 0 . 0 1 3~~ ; S", SO.,, BrO', absent; Chloride ion 0.3% (calculated as calcium chloride).The product was used for the manufacture of bromine salts for pharmaceutical purposes. SummaryDuring the war, large quantities of calcium bromide were produced at the Dead Sea works of Palestine Potash Ltd. from hydrobromic acid obtained through the reduction of bromine by means of sulphur.The reaction between bromine, sulphur and water is strongly exothermic ; at low temperatures its rate is slow and it cannot be brought to completion owing to inhibition by the reaction products. At temperatures above 70' this inhibition effect disappears and the rate of reaction increases considerably. The industrial process here described was carried out at the boiling point of the reaction mixture. The problem of dissipating the heat evolved in the reaction was solved by bringing the vapours of the boiling mixture into contact with the ice. The condensed vapours and the water formed by the melting of the ice were allowed to flow back into the reaction vessel. This procedure allows the use of a reaction vessel made of a material of low heat conductivity, but resistant to corrosion. to commemorate the 70th anNvcrsary of Dr. Chaim Weizmann, Rchoboth, Palestine Bloch, H., Goldschmidt, P, Littman, H., Palestine Pat. No. 1618 I. Failure to determine the 1-2% of non-carbohydrate constituents present.2. The use of methods not giving complete drying for the determination of the moisture content.3. The use of insufficiently accurate methods for the detcrmination of the dextrose produced. 4. Failure to allow for any decomposition of the dextrose produced. 5. Incomplete hydrolysis of the starch. The starch sitbstrute.-The starch used in the present investigation was a lintnerised wheat starch prepared by treating B.D.H.:wheat starch with 2 I N-hydrochloric acid (250 g. starch * Specified as zoo ml.:of starch suspension and 20 ml. HCl of sp.gr.
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