Formic acid

“ Table of the Combinations of Formic Acid, with the Salifiable Bases, in the Order of Affinity.
Note.—All unknown to the ancient chemists.—A. [Pg 283]
Sect. XLI.—Observations upon Formic Acid, and its Combinations.
This acid was first obtained by distillation from ants, in the last century, by Samuel Fisher. The subject was treated of by Margraff in 1749, and by Messrs Ardwisson and Ochrn of Leipsic in 1777. The formic acid is drawn from a large species of red ants, formica rufa, Lin. which form large ant hills in woody places. ”

“ Many yeasts when grown in presence of sodium formate decompose a certain proportion of it, whereas in absence of formate they actually produce a small amount of formic acid—the absolute quantities being usually of the order of 0·0005 gram molecule (0·023 gram) per 100 c.c. of medium in 4 to 5 days. Only in the case of S. validus did the consumption of formic acid in 5 days reach 0·0017 gram molecule (0·08 gram) . Somewhat similar but rather smaller results were given by yeast-juice, a small consumption of formic acid being usually observed. ”

“ It is extremely corrosive, and rapidly destroys the texture of living organic substances. The products of the other processes are very dilute, and possess the above properties in only a minor degree. They may all be purified and concentrated by saturating them with pure carbonate of sodium or of potassium, and after subjecting the liquid to a gentle heat for a short time, and liberating the formic acid from the salt by means of dilute sulphuric acid, finally submitting the mixture to distillation, when the hydrated acid will come over perfectly pure. ”

“ DESORPTION EFFICIENCY STOCK SOLUTION, 51.5 mg FORMIC ACID/mL Pipet 6 mL of 88% formic acid into a 125-mL volumetric flask. Make to volume with dioxane. For standardization, appropriate aliquots are withdrawn, diluted with deionized water, and analyzed as in steps 9 through 15. ”

“ When placed in contact with a solution of formic acid it converts it, with copious effervescence, into carbonic acid; alcohol, dropped upon it, becomes changed by oxidation into acetic acid, the rise of temperature being often sufficient to cause inflammation; exposed to a red heat, it shrinks in volume, assumes the appearance of spongy platinum, and, for the most part, loses these peculiarities. That prepared with zinc explodes, when heated, like gunpowder. The spongy platinum is obtained by igniting the ammonium platinic chloride at a red heat. ”

“ For now, through our telecto-scope we could see that our planet had been subtly altered! A few symmetrical lines had appeared on the face of Diskra, as if a cosmic hand had drawn straight lines across with mathematical precision!
Not until we had safely landed, did we learn the truth. O joyous news! The hordes of Termans had been repulsed and were even then being slowly driven back! Our scientists had created in the laboratories a type of formic acid somewhat similar to the vesicatory secretion occurring within our own bodies—but infinitely more deadly! ”

“ I do not know that the artificial method can at present compete with the natural, but it will probably do so before long, if it does not now. Little did the discoverer dream of the result when he undertook his investigation. When glycerin and oxalic acid are mixed, and the mixture distilled, the chief product under ordinary circumstances is formic acid, a substance found in nature in the bodies of certain ants. Formic acid had been made by the method mentioned for a number of years before it was noticed that something else is formed at the same time. ”

“ The salts of the acid are known as formates, and are mostly soluble in water, those of silver and lead being the least soluble. They crystallize well and are readily decomposed. Concentrated sulphuric acid converts them into sulphates, with simultaneous liberation of carbon monoxide. The calcium salt, when heated with the calcium salts of higher homologues, gives aldehydes. The silver and mercury salts, when heated, yield the metal, with liberation of carbon dioxide and formation of free formic acid ”

“ Frankland and Frew, in a paper on a pure fermentation of mannitol and dulcitol163 have shown the hydrogen and carbon di-oxide given off were produced by the decomposition of formic acid, the ferment producing formic acid and the latter immediately splitting up into an equal number of molecules of carbonic anhydride and hydrogen. We have every reason to believe, from experiments which will be included in the third section of the paper, that the source of the H and CO2 is the same in the fermentation we are considering. ”

“ Of the rest the sulphuric-acid plant was most thriving, then the hydrochloric-acid plant, and last, and just alive, the plant treated with formic acid. Analyses of the ashes of the plants showed that the acid waters tended to introduce organic ingredients into their tissues. Of hyacinth-bulbs treated in a similar way, only the one treated with tannic acid developed roots. The hydrochloric-acid bulb died, and the sulphuric-acid bulb a month later. After the tannic-acid one, a bulb treated with oxalic acid did best. Tannic acid seemed to increase the intensity of the color of the flower. ”

“ On the other hand, hydrochloric acid is not poisonous either to animals or to Drosera, and induces only a moderate amount of inflection. Many acids excite the glands to secrete an extraordinary quantity of mucus; and the protoplasm within their cells seems to be often killed, as may be inferred from the surrounding fluid soon becoming pink. It is strange that allied acids act very differently: formic acid induces very slight inflection, and is not poisonous; whereas acetic acid of the same strength acts most powerfully and is poisonous. ”

“ When you have treated wet specimens with anything acid, do remember to neutralise the acid residues as soon as possible. The same applies if you have preserved them with anything that gradually produces acid; For example, formaldehyde gradually reacts with oxygen to produce formic acid. In due course it destroys shells, and even fine bones and teeth. As a buffer, ammonia is cheap, effective and safe in reasonable circumstances. However, it is too volatile to be a reliable buffer against long term acidity. ”

“ Oil of turpentine, like volatile oils in general, undergoes on exposure to the air certain alterations giving rise to what is called resinification. The formic acid which is produced in small quantity during this change characterizes it as one of oxidation; the chief products however are not exactly known, and not one of them has been proved identical with any natural resin. The common assumption that resins are produced from volatile oils by simple oxidation, is consequently not yet entirely justified. ”

“ Spike appropriate amounts of calibration stock solution or a dilution thereof, onto sorbent tubes. b. Desorb in the same manner as field samples. c. Analyze working standards together with samples and blanks (steps 12 through 14) . d. Prepare a calibration graph of peak height vs. amount (μg) of formic acid per 10 mL of sample. NOTE: Apply the conversion 1 μg formate = 1.022 μg formic acid. (Optional) Determine recovery for each lot of silica gel used for sampling in the concentration range of interest. ”

“ Formiate. Salts, in which one atom of hydrogen in formic acid is replaced by a metal or other basic radical. They are best obtained either by direct saturation of the acid, or by double decomposition; most of them are very soluble, and are decomposed by hot oil of vitriol. Formate of ammonium crystallises in square prisms; formate of sodium, in rhombic prisms; formate of potassium is deliquescent, and crystallises with difficulty; the formates of barium, calcium, magnesium, and strontium, form small prismatic crystals ”

“ Lactic acid is in fairly common use as a deliming agent. In practice 1 per cent. lactic acid (50 per cent. strength) calculated on the wet weight of pelt, is used, added gradually in small quantities. This does not remove the whole of the lime, but sufficient for the skins to puer quickly.
Some tanners measure their acid per dozen skins. In a case which came under my notice, 1200 c.c. 90 per cent. formic acid were being used for ten dozens medium goat skins at a temperature of 35° C., time 1 1/4 hours. ”

“ Formic acid is a powerful irritant. It was originally obtained by pounding ants in a mortar, and distilling their remains. It is now produced much more easily, and has been shown to be secreted not only by ants but by other insects, and this secretion is apparently exaggerated when the insect is attacked or irritated. ”

“ When heated with dilute sulphuric acid to 130° C., under pressure, it is resolved into formic acid and acetaldehyde. Chromic acid oxidizes it to acetic acid and carbon dioxide; potassium permanganate oxidizes it to pyruvic acid; nitric acid to oxalic acid, and a mixture of manganese dioxide and sulphuric acid to acetaldehyde and carbon dioxide. Hydrobromic acid converts it into α-brompropionic acid, and hydriodic acid into propionic acid. ”

“ Thus the catalytic effect of a platinum solution is halved by prussic acid, even when the concentration of the latter is only 0.0014 milligram per liter; the effect of this substance is, however, only temporary, and the solution gradually recovers in course of time. A large number of substances exert this poisoning action to a greater or less extent, but there are some which intensify the catalytic action of the colloidal platinum, among them being formic acid and dilute nitric acid. ”

“ The solution must be prepared fresh daily. Loss of formic acid was observed after 24 h. Pipetting below the liquid level of the standard will minimize loss of formic acid from evaporation. APPENDIX B: SAMPLING TUBE PREPARATION Silica gel cleaning procedure: Add 500 to 600 mL deionized water, slowly and with stirring, to ca. 200 mL volume of silica gel in 1-L beaker. When exothermal reaction has subsided, heat in boiling waterbath for ca. ”

“ The leaves of Prunus Lauro-cerasus L., the bark of P. Padus L., and the organs of many allied plants, also contain emulsin or a substance analogous to it, not yet isolated. In the seeds of various plants belonging to natural orders not botanically allied to the almond, as for example in those of mustard, hemp, and poppy, and even in yolk of egg, albuminous substances occur which are capable of acting upon amygdalin in the same manner. Boiling dilute hydrochloric acid induces the same decomposition, with the simultaneous production of formic acid. ”

“ Lyte for me, if he will be so good as to explain the discrepancy which appears between his "new processes," as given in the Journal of the Photographic Society of Sept. 21, and "N. & Q." of Sept. 10? In the former he says, for sensitizing, take (amongst other things) iodide of ammonia 60 grains: in "N. & Q.," on the contrary, what would seem to be the same receipt, or intended as the same, gives the quantity of this salt one fourth less, 45 grains—a vast difference. Again, in the developing solution the quantity of formic acid is double in your paper what it is in the journal. ”

“ RANGE:
0.5 to 10 mg per sample
ESTIMATED LOD: 0.01 mg per sample [2]
ˆ ) : 0.058 [1] OVERALL PRECISION (S rT ACCURACY:
± 15.5%
PRECISION (Sr) :
0.007 @ 0.3 to 5 mg per sample [1,3]
APPLICABILITY: The working range is 2 to 40 ppm (5 to 100 mg/m 3) for a 100-L air sample. High (90% RH) humidity during sampling did not cause breakthrough at 39 mg/m 3 for 4.6 hrs [1] .
INTERFERENCES: Formic acid contains a small amount of acetic acid which gives a significant blank value. High-purity formic acid must be used to achieve an acceptable detection limit. ”

“ If, however, morphin was administered after increased acidity had been produced by any stimulus, or by inhalation anesthesia, then the time required for the restoration of the normal alkalinity was much prolonged, and in some instances the power of acid neutralization was permanently lost.
After excision of the liver, the normal H-ion concentration was maintained for periods varying from one to several hours, after which the concentration (acidity) began to increase as the vitality of the animal began to decline, the concentration (acidity) increasing rapidly until death. ”

“ Acetate of lead is now added to the filtrate until no further precipitation occurs; the liquid is then boiled and filtered. The meconic acid remains on the filter as meconate of lead, while the filtrate contains the morphine as acetate. The liquid is freed from excess of lead by passing through it a current of sulphuretted hydrogen, filtered to remove the precipitated sulphide of lead, and the [Pg 340] resulting liquid evaporated to an extract on a water bath, and treated with alcohol. The alcoholic solution on evaporation gives acetate of morphine, which may then be tested. ”

“ When powdered aloine is thrown, in small quantities at a time, into cold fuming nitric acid, it dissolves without evolving any nitrous fumes, and forms a brownish-red solution. On adding a large quantity of sulphuric acid, a yellow precipitate falls, which, when it is washed with water to remove all adhering acid and then dried, explodes when it is heated. ”

“ It is only slightly soluble in water, alcohol, chloroform, liquid petrolatum and vegetable oils. Alkalies and strong acids decompose it. It is stable at temperatures below 120 C.
When about 1 gm. of the salt is boiled with 10 c.c. of sodium hydroxide test solution, the liquid filtered, and the filtrate acidulated with sulphuric acid, the white curdy precipitate produced, when washed and dried, melts at 90 to 95 C. (tri­brom­phenol) . The contents of the filter dissolve completely in dilute hydrochloric acid (insoluble inert material) . ”