d. From oil of aniseed, 1⁄4 oz.; nitrous acid, 2 to 3 drops; musk, triturated with a little powdered sugar, 1 gr.
RA′ZORS. See Papers, Paste, and Shaving.
REA′GENTS. See Tests.
REAL′GAR. This valuable red pigment is the bisulphide of arsenic. It is found native in some volcanic districts; but that of commerce is prepared by distilling, in an earthen retort, arsenical pyrites, or a mixture of sulphur and arsenic, of orpiment and sulphur, or of arsenious acid, sulphur, and charcoal, in the proper proportions. See Disulphide of Arsenic.
RECOMMENDATIONS TO FARMERS. A series of valuable suggestions, intended for the guidance of farmers in the purchase of manures and cattle-feeding materials have lately been
issued by the Royal Agricultural Society of England. In substance they are as follows:—In the purchase of feeding-cakes, the guarantee of ‘pure’ should be insisted upon, since this means a legal warranty that the article is produced from good clean seed. The terms ‘best’ and ‘genuine’ are of no value, and should be objected to. Furthermore, the sample should be subjected to analysis. For this purpose a sample should be taken out of the middle of the cake, whilst the remainder of the cake from which the sample has been selected, should be sealed up and placed aside for reference in case of dispute.
The following advice is given to farmers about to purchase manures:—Raw bones or bone dust should be purchased ‘as pure,’ whilst they should be guaranteed to contain not less than 45 per cent. of tribasic phosphate of lime, and 4 per cent. of ammonia. ‘Boiled bones’ should be purchased as ‘pure’ boiled bones, guaranteed to contain not less than 48 per cent. of tribasic phosphate of lime, and 13⁄4 per cent. of ammonia. Dissolved bones vary so greatly that the buyer should insist on a guarantee of quality under the heads of ‘soluble phosphate of lime,’ ‘insoluble phosphate of lime,’ and ‘nitrogen’ or ‘ammonia,’ also for an allowance at current rates for each unit per cent. if the bones should prove on analysis to contain less than the guaranteed per-centages, &c. It should be insisted that mineral superphosphates are delivered dry and in good condition, and be guaranteed to contain a certain per-centage of soluble phosphates at a certain price per unit per cent. No value is to be attached to ‘insoluble phosphates.’ Compound artificial manures, which are rarely used, should be purchased on exactly the same terms. Nitrate of soda should be purchased on exactly the same terms. Nitrate of soda should be guaranteed to contain 94 to 95 per cent. of pure nitrate. Sulphate of ammonia should yield 35 per cent. of ammonia. Peruvian guano should be sold under that name, and guaranteed to be in a dry, friable condition, and to contain a certain per-centage of ammonia.
In buying artificial manures the purchaser is recommended to obtain a guarantee that they shall be delivered in a sufficiently dry and powdery condition to allow of sowing by the drill.
Samples, taken out of three or four bags, should be well mixed together, and they should be analysed not later than three days after delivery. Two tins, holding about half a pound each, should be filled in the presence of a witness, sealed up, one sent to the analyst, and the other retained for future reference.
RECTIFCA′TION. The redistillation, &c., of a fluid, for the purpose of rendering it purer.