On the structure of the raphides of Cactus enneagonus / by John Quekett.

  • John Thomas Quekett
Date:
[1852]
Catalogue details

Licence: Public Domain Mark

Credit: On the structure of the raphides of Cactus enneagonus / by John Quekett. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    matter were not confined to the investing membrane, but inti mately mixed up or incorporated with every atom of the lime. 1 have this day examined some sections of the Soap wood of China, in which stellate masses of crystals are very abundant. If these be acted on by dilute hydrochloric acid, the earthy constituent will disappear, but a cast of the original mass will be preserved in what may be termed organic matter. This point, however, is the one which requires to be carefully ex- amined by persons more skilled than myself in the science of organic chemistry. As far as my observations have hitherto gone, it would appear to be a rule that we rarely, if ever, find inorganic material in the vegetable or animal kingdom, except in the crystalline state, without the existence of an organic basis. Since the above was written, my friend Dr. Lionel Beale has been kind enough to examine the raphides in question, and the following is his report on the subject. “ A few of the white globular crystalline masses were treated with boiling distilled water, and the aqueous solution, after being filtered, was evaporated to a small bulk. Upon examining the residue by the microscope, numerous small colourless crystals, in the form of obtuse rhomboids, were observed. The residual solution was found to give precipi- tates insoluble in strong nitric acid, with solutions of nitrate of barytes and nitrate of silver, proving the presence of chlorine and sulphuric acid. Oxalate of ammonia gave a pre- cipitate insoluble in acetic acid, but soluble in strong nitric acid, showing the presence of lime. “ Hence boiling distilled water extracted a small quantity of soluble matter, which contained lime, chlorine, and sul- phuric acid, probably in the form of sulphate of lime and chloride of sodium. “ Acetic Acid.—The crystalline masses were not affected by boiling acetic acid. “ Potash.—No observable action was produced by boiling a few of the masses in solution of caustic potash. “ Nitric Acid.—Upon the addition of strong nitric acid, effervescence occurred with some lew of the bodies as they dissolved, but upon the majority this re-agent exerted little action in the cold. When the mixture was boiled, complete solution immediately took place. “The acid solution was evaporated to dryness; the dry residue was boiled in distilled water, and the filtered solution, after concentration, was allowed to remain in a still place lor some time. Lfpon examining the residue with the microscope
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