First report of the Royal Commission appointed to inquire into arsenical poisoning [1900] from the consumption of beer and other articles of food or drink.

  • Great Britain. Royal Commission on Arsenical Poisoning.
Date:
1901-1903
Catalogue details

Licence: In copyright

Credit: First report of the Royal Commission appointed to inquire into arsenical poisoning [1900] from the consumption of beer and other articles of food or drink. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    1901. cleaied up yet; and pcirhaps some opportunity may bo given to me on a future ocoadioii to bring them before the Cijmmissdon. 2367. We shall be ven^ glad to hear anytliing you can gave us, either now or at some other time?—I am. en- gaged witli my fello.w-expeits in making investigations as to the source^ of arsenic in beer, and the means by wliicJa they might be avoided—ooke, coal, acids, malts, liop^, and so on, and our experiments are nut yet com- pleted. 2368. As a rule, can arsenic be easily removed from the chemical known to contain it; for instance, from boric acid or borax?—^No. 2369. I am told that it is quite easy to remove it froijn sulphuric acid?—Yes. I ha-\'e seen pi-aolioally the whole of it removed. 2370. But not from boric aoid?—No. 2371. {Dr. Wliifclcgge.) How does the difficulty arise in the case of boric acid ?—If you re-crystcdlise it again and again some of the arsenic will still attach itself tio the boric acid or the borate. When you get two sub- stances together in the form of crj'stais it is often very ditfieult to entirely separate one from the other by ro- crystalisattiuai. 2372. (Chairman.) Can the arsenic not be precipitated by sulphuretted hydrogen or otherwise from a solution of the substance?—^In the quantities present I do not think it is practicable. For instance, in the samples of borax I have examined when you dissolve the borax and axridify it to keep the boric acid in solution you ha^-e sticii •I dilute solution that the arsenic cannot be precipitated by sulphuretted hydrogen ; whereas if you distill the l)oric acid or the borax with hydrochloric acid, you get the distillate, but the difficulty of separating it com- ;u«roially, ito remove the least trace, is enormous, and 1 believe I may say quite unnecessary and no source of danger to the public. 2373. {Chairman.) Is it practically innocuous?—Yes. 2374. {Professor Thorpe.) In thiat particular case I quite agree that the. amount is negligilDlf, but if it were a matter of importance to free it even from boric acid or borax, I do not think there would be any difficulty in doing it ?—I do not think the difficulty would be insuper- able, ^but it would be a very troublesome and costly process. I think tlie chemist, if he makes up his mind to separate any ingredient, can generally manage to do it in the end. 2375. Talve the ca.s;e of the boracic acid. That perliaps would ibe remarkably easy, because the cin-ious point about 'boracic acid is that, although, pretty soluble in hot wartier, it is not so in cold water, so that if one were to take borax or 'borate of lime containing arsenic, and one were to treat it, as one does in the process of manufac- ttrre, with hydrochloric aoid, the gi-eater quantity of the arsenic would remain in the motliier liquor and the boracic acid would be tlirown out ?—Yes. 2376. That would leave it practically, or very nearly, free, and a repetition of that process would practically get down tl-.e arsenic to a negligible quantity, would it not ?—Yes, in the greater proportions of l>oric or boracic acid I have examined the quantity is very small ; it does not .amotuit to more than 1-20, 1-30, or 1-100 of ai grain per lb. It is negligible as regards health purposes. 2377. But if I mighit be allowed to jiursue that, of oour.5;i you would draw a sharp line of distinction between arsenic introduced into products which may enter into the oompounds of food and sulphuric acid, and the arsenic ]ntToduee<l into products where tlie arsenic, sO' to speak, is of a natural origin. Now, I presume it would not be difficult to exclude arsenic introduced into foods by sul- phuric acid incidentally?—No, it would not. 2378. It might be more difficult to exclude it in articles of food deiived from natural products which themselves might contain arsenic ?—Yes. 2379. But in so far as these natural products were de- cts rived from the U!^^ of arsenica.ted manures, which were the'mselve.s derived from oil of vitriol, it ought not to be difficult to exclude them ?—No ; prohibit the use of arsenical sulphuric acid in the preparation of manures and that s-ource is removed. 2380. How manv substances occtir to you containing arsenic derived from what may be called a natural origin? —It is difficult to say ; but the borates, the phosphates, phosphate of sodium, and .so on. 2381. Mav I ask you about the phosphate of soda? We of know that occasionally samples of phospliates of soda are 4575. found to be associated with arsenate of soda, but in that case how is the arsenic derived ?—It may be from the sul- phuric acid, or it may be possibly from the carbonate of soda. 2382. But even from the carbonate of soda, if it is in tJie oarbcnate of soda it has been derived from tlie sul- phuric acid ?—^Yes, soda made fix>m svlpliuric add. 2383. By the Leblanc process it would be obtained from ihe sulphuric acid ?—-Yes. 2384. !Lf W9 exclude it from the sulphuric acid wo can also exclude it from the soda?—Yes. 2385. Whiat other source of arsenic could there be in phosphate of soda other than tlve sulphuric acid and tlie carbonate of soda?—I think practically none. 23S6. In that way, therefore if it were required we could free the phosphate of soda from even the last traces, (jr almost the last trajes, of arsenic acid?—Yes. 2387. I shotild like to gather from you wliat other articles of food other than those which are prepared by the intervention of oil of vitriol there are winch could contain arsenic acid or ansenious compounds generally ?— I think it is difficult to run oiver everytliii'jg ; but the other sources, I think, are negligible. 2383. Do j-ou mean they axe not at aU a matter of .'■.ijrious moment?—I think not. 2389. that if steps could be taken to exclude arsenic from the oil of vitriol practically we sliould abolisih the greater portion of the danger?—^Yes ; you would not get it in the hydrochloric acid. 2390. Which is an incidental product, in the same way, of sulphuric acid?—Yes. 2391. In fact, it is the arsenic from the pyrites wliidh is practically the origin of the large portion of arsenic which is found in sulphuric acid and sulphuric acid deri- vati v-3;3 ?—Yes, and that need not involve the abolition of j)yiiitic acid, because pyritic acid can be freed from arsenic <fnd rendered (juite as free as sulphuric acid made direct from brimstone. 2392. Are you conversant withi the mode of manufac- ture of oil of vitriol on a large scale ?—I have visited wirrks. I do not advise any works, but I visit them from time to time. I spent a whole day last week in a vitriol works. 2393. Are you familiar with tlio teolinology ?—Fairly we'll. 2394. The arseniotrs oxide in 'tlie oil of vitriol comes, of course, from the double sulphide and arsenide of iron present in the pyrites?—^Yes. 2395. Wihen the p'yrites is roasited in die kiln the arsenious oxide is volatilised ?—^Yes. 2396. Is there any process known to you by wliidh tlio greater portion of that arisenious oxide can be taken out before it gets iiuto the vitriol cliaimber ?—^You are sipeak- mg of the ordinaiy processes ? 2367. Yeis ?—'Yes. A great deal lof it may- bo takm out. In the Glover bower it is pxiacticalily all 'taken out. 2398. Before it even gets 'to itllie GHbver toiwer, is it not known to you that at all events tlie greater portion of the arsenious oxide may be removed ?—^Yes, a great deal is deposiited in the Hues, of course, and in tlie isyn- tlietic aoid it is the essence of itlie process that all the arisenic should be taken out. You are acquainted, of course, with the process employed here and in Germany, that in the preparation of synthetic acid the sulphur is converted into tri-oxide, and that is dissolved in water, and the di-oxide being convertod into the tri-oxide by passing it with air over finely divided platinum, if the di-oxide is not entirely deprived of arsenic before it passes over the platinum, the process is vitiated by the platinum becoming choked with the crystals of arsenious oxide. I have; seen it done. The di-oxidc' is wiashel and washed until, when you look through pe'rliaps 8 or 10ft. of tlie gas, with either an electric or bright burner, as long as the atmosphere above the wash water blurs the flame in the slightest it is not free from suspended particles of arsenic. In one' works in thei neighbour- hood of London I sujopose they make 500 or 600 tons of this synthetic acid evei'^- week, and of course they make other acid. 2399. (Clininiiaii.) Isl tli'at from pyrites cr from sul- phur ?—It is made from jjyrites or from suliihur, but I tliink mostly from pji-ites. But even in the old process of the chamber acid the greater part of the arsenic is got rid of before the acid reaches the chamber. M 2 Dr. I. Steven 13 ISIar. 1901. De-arseni- cated pyritic ecid may be as free from arsenic as brimstone aoid. Synthetic sulphuric acid.