Glass phials

A very elegant solution to this problem is the mid-point method (Rutherford, 1962), and its subsequent developments (Pask, Plesch and DiMaina, 1981). The method is suitable for weighing small quantities (ca. 0.1-4.0 g) of liquids, solutions or solids in phials filled under vacuum and it is described in detail below, because although now quite old, it does not seem to be very widely known. 

The accuracy of the method is very dependent on the care and reproducibility with which the lengths of tubing are cut and the breaks are made, but under optimum conditions has been estimated as +1.7 x 10 g. 

In order to improve the reproducibility with which lengths of tube can be cut and marked at their mid-point, a tube cutter has been designed. Such a cutter is not available commercially, but it can be made in any well-equipped metal workshop from the published description (Pask, Plesch and DiMaina, 1981). 

Although the mid-point method requires practice, it is not as time-consuming as it may appear at first sight, since it is possible to fill batches of up to 20 phials in a single operation. This has the distinct advantage that the impurities are the same, at least from this source, for a particular set of experiments in which these phials are used. 

As explained on p. 22, thin glass phials cannot be tested for leaks directly with a Tesla coil, and must therefore be tested by the other method (Section 2.3.2) if they are suspected of being leaky. If a phial is leaky, it must be fused off and discarded. Because of the deleterious effect of a narrow tube on the pumping speed, the apparatus for filling phials should be joined to the vacuum line as close as possible to the pumps. 

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FIGURE i6. David Ryckaert, Scholar with Homunculus in Glass Phial, seventeenth century. Reiss-Engelhorn Museen Mannheim. Photo credit Jean Christen. 

Therefore, in order to meter small quantities of materials in vacuo, the use of glass phials or calibrated break-seals, described in Sections 3.1.2 and 3.1.3. respectively, is recommended. Even smaller quantities of moderately volatile materials can be dosed by means of calibrated vapour-dosing bulbs (see Section 3.1.5). 

Static mode the sample (liquid or solid matrix) is placed in a glass phial capped with a septum such that the sample occupies only part of the phial s volume. After thermodynamic equilibrium between the phases has been reached (1/2 to 1 h), a sample of the vapour at equilibrium is taken (Fig. 20.4). Under these conditions, the quantity of each volatile compound present in the headspace above the sample is proportional to its concentration in the matrix. The relationship between the amount of sample injected into the gas chromatograph and its concentration in the matrix can be obtained by calibration (using internal or external standards). 

The golden sap which we received after the exaltation of our stone, our elixir, is also called Lac virginis or Virgin Milk, it will now be placed into the philosophical egg (into a glass Phial) which is then hermetically sealed. Two-thirds of the receptacle must be empty so that the materia can circulate. 

Rub them diligently together in a glass mortar, until, after the effervescence has ceased, they unite into a violet coloured mass. This must be wrapped up in blotting paper, and first dried on a chalk stone, and afterwards by a gentle heat. The product must be kept in a glass phial well stopped. 

Figure 8. Radiolysis experiments on cement pastes leading to know the total pressure and the composition of gases according to the duration of gamma irradiation 3) sealed glass phial around a test-bar 4x4x16 cm b mini-containers out of stainless of500 cm (allowing a quasi-integral filling of cement paste) with outlets for P(H2) measurement in line.

Homberg s Pyrophorus, Stir equal parts of iiltun and brown sugar (or 3 parts alum and I part wheat flour) in an iron ladle over tUo fire until dry then put it into an earthen or coated glass phial, and keep it at a red heat so long as flame is emitted it must then be carefully stopped up and cooled. 

Nitrous acid vapour (nitrogen dioxide, NO2) was made by the action of concentrated nitric acid on bismuth and shut up in dry glass phials with ground glass stoppers, being collected by displacement of air (perhaps the first use of this process), the delivery tube being bent downwards, in order to be inserted into the mouths of the phials that were to receive the vapour. It could not be collected over mercury, which absorbed it and was attacked. Nitrous... 

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