Companion to the latest edition of the British pharmacopoeia : comparing the strength of its various preparations with those of the United States and other foreign pharmacopoeias to which are added non-official preparations and practical hints on prescribing / by Peter Squire.

Squire, Peter Wyatt, Sir, 1847-1919.

Date:: 1874

Credit: Companion to the latest edition of the British pharmacopoeia : comparing the strength of its various preparations with those of the United States and other foreign pharmacopoeias to which are added non-official preparations and practical hints on prescribing / by Peter Squire. Source: Wellcome Collection.

348/480 (page 312)

$centimetres of solution, 100 cubic centimetres of this solution contain T^th of an equivalent in grammes of the Bichromate of Potash ( = 1-475 grammes) and are capable of converting y^th of sis equivalents of iron (168 grammes) from the state of protosalt to that of persalt. This solution is used for determining the proportion of Protoxide of Iron in the following preparations. It is known that the whole of the protosalt has been converted into a persalt when a minute drop of the liquid, placed in contact with a drop of the solution of Eed Prussiate of Potash on a white plate, ceases to strike with it a blue colour. Britisli Weiglita Metrical Weight3 and Measures. and Measures. G-rains Grain- Grammes weight of measures of or weight of = C. C. of Substance. Vol. Sol. Substance. Vol, Sol. Ferri Arsenias. . . 20 = 170 or 2-0 = 17-0 „ Carb. Sacch. . . 20 = 330 or 2-0 = 330 „ Oxid. Magn. . . 20 83-0 or 2-0 = 83-0 „ Phosphas . . . . 20 = 250 or 2-0 = 25-0 VOLUMETEIO SOLUTION OF HYPOSULPHITE OF SODA. (Hyposulphite of Soda Crystallized, ]S'aO,S202+5HO = 124, or K-a2H2S204.4H20 =248,) Take of Hyposulphite of Soda, in crystals, 280 grs.; Distilled Water, a sufficiency: dissolve the Hyposulphite of Soda in 10,000 grain-measures of water. Fill a burette with this solution and drop it cautiously into 1000 grain-measures of the Yolumetric Solution of Iodine, until the brown colour is just discharged. Note the number of grain-measures (n) required to produce this effect; then put 8000 grain-measures of the same solution into a gradu- ated jar, and augment this quantity by the addition of Distilled Water, until it amounts to sooomiooo grain-measures. If, for example, w=950, the 8000 grain-measures of solution should be diluted to the bulk of ^ ° ^ ^ ° ° ° = 8421 grain-measures. 1000 grain-measures of this solution contain -^th. of two equivalents in grains (= 24*8 grains) of the Hyposulphite, and therefore cor- respond to-jijth of an equivalent in grains ( = 12-7 grains) of Iodine. Grammes and cubic centimetres may be employed instead of grains and grain-measures, but for convenience -^th. of the numbers should be taken. 100 cubic centimetres of this solution contain y^th of two equivalents of Hyposulphite in grammes ( = 2*48 grammes), and therefore correspond to yioth of an equivalent in grammes (1*27 grammes) of Iodine. The solution is used for testing the following substances. In each case, excepting that of Iodine, a solution of Iodide of Potassium and Hydrochloric Acid are added to the substance, and the amount of Iodine so liberated is indicated by this solution. British Weights Metrical Weights and Measures. and Measures. Grains weight of Substance. Grain'- = measures of Vol. Sol. or y Grammes weight of = Substance, \ C. C. of Vol. Sol. Calx Chlorata . 10-0 = 850 or 1-00 = 85-0 = 1000 or 1-27 = 100-0 Liq. Calc. Chlorates . 60-0 = 500 or 6-00 = 50-0 ), Chlori . . . . 439.0 = 750 or 43-90 = 75.0 „ Sodse Chloratse . 70-0 = 500 or 7-00 = 50-0$