Solution of ammonia is now seldom made by the druggist, or on the small scale, the large manufacturing chemists supplying it at a very low rate, and of very superior quality. In the shops it is kept of two or three strengths. The estimation of the strength of ammonia solutions in commerce is known as ammonimetry, and depends upon their specific gravities. The per-centage richness of solutions of ammonia, or of its carbonates, may be most accurately determined, by ALKALIMETRY. For all the ordinary purposes of commerce, and of the laboratory, the strength of pure solutions of ammonia may, however, be inferred, with sufficient correctness, from their density; and to this the term AMMONIOMETRY is usually restricted. The specific gravity of the sample being found either by the hydrometer[45] or specific gravity bottle, in the usual manner, its per-centage strength may be seen by inspection of the following _Table_ and the _Table_ on p. 127. [Footnote 45: An hydrometer specially weighted and graduated for this purpose is called an AMMONIM′ETER, AMMONIOM′ETER, or AMMO′NIA-ME′TER (AMMONIM′ETRUM, AMMONIOM′ETRUM, &c., L.)] TABLE I.——_Showing the per-centage of_ PURE AMMONIA, _and of_ AMMONIA-WATER _of_ ·9000, _in Water of Ammonia, of the given specific gravities, at_ 60° Fahr. By Dr URE. ------------+------------+----------------+------------ Sp. Gr. by | Water of | Pure | Water, experiment. | Ammonia | Ammonia, per | per cent. | of 900, | cent. | | per cent.| | ------------+------------+----------------+------------ ·9000 | 100 | 26·500 | 73·500 ·9045 | 95 | 25·175 | 74·825 ·9090 | 90 | 23·850 | 76·150 ·9133 | 85 | 22·525 | 77·475 ·9177 | 80 | 21·200 | 78·800 ·9227 | 75 | 19·875 | 80·125 ·9275 | 70 | 18·550 | 81·450 ·9320 | 65 | 17·225 | 82·775 ·9363 | 60 | 15·900 | 84·100 ·9410 | 55 | 14·575 | 85·425 ·9455 | 50 | 13·250 | 86·750 ·9510 | 45 | 11·925 | 88·075 ·9564 | 40 | 10·600 | 89·400 ·9614 | 35 | 9·275 | 90·725 ·9662 | 30 | 7·950 | 92·050 ·9716 | 25 | 6·625 | 93·375 ·9768 | 20 | 5·300 | 94·700 ·9828 | 15 | 3·975 | 96·025 ·9887 | 10 | 2·650 | 97·350 ·9945 | 5 | 1·325 | 98·675 ------------+------------+----------------+------------ ⁂ Strengths corresponding to sp. gr. which are not in the above _Tables_ may be found by the ‘method of differences’ explained under ALCOHOLOMETRY.