A Dictionary of Arts, Manufactures and Mines / containing a clear exposition of their principles and practice - Andrew Ure

The cylinder apparatus is now much esteemed by many manufacturers. [Fig. 747.] represents, in transverse section, a bench of iron cylinder retorts, as built up in a proper furnace for producing muriatic acid; and [fig. 748.] a longitudinal section of one retort with one of its carboys of condensation. a is the grate; b, a fireplace, in which two iron cylinders, c c, are set alongside of each other. They are 5¹⁄₂ feet long, 20 inches in diameter, about ¹⁄₄ of an inch thick, and take 1·6 cwts. of salt for a charge; d is the ash-pit; e, e, are cast-iron lids, for closing both ends of the cylinders; f is a tube in the posterior lid, for pouring in the sulphuric acid; g is another tube, in the anterior lid, for the insertion of the bent pipe of hard glazed stone-ware h; i is a three-necked stone-ware carboy; k is a tube of safety; l, a tube of communication with the second carboy; m m, m m, are the flues leading to the chimney n.

After the salt has been introduced, and the fire kindled, 83¹⁄₄ per cent. of its weight of sulphuric acid, of spec. grav. 1·80, should be slowly poured into the cylinder through a lead funnel, with a syphon-formed pipe. The three-necked carboys may be either placed in a series for each retort, like a range of Woulfe’s bottles, or all the carboys of the front range may be placed in communication with one another, while the last carboy at one end is joined to the first of the second range; and thus in succession. They must be half filled with cold water; and when convenient, those of the front row at least, should be plunged in an oblong trough of running water. The acid which condenses in the carboys of that row is apt to be somewhat contaminated with sulphuric acid, muriate of iron, or even sulphate of soda; but that in the second and third will be found to be pure. In this way 100 parts of sea-salt will yield 130 parts of muriatic acid, of spec. grav. 1·19; while the sulphate of soda in the retort will afford from 208 to 210 of that salt in crystals.

It is proper to heat all the parts of the cylinders equably, to insure the simultaneous decomposition of the salt, and to protect it from the acid; for the hotter the iron, and the stronger the acid, the less erosion ensues.

Some manufacturers, with the view of saving fuel by the construction of their furnaces oppose to the flame as many obstacles as they can, and make it perform numerous circulations round the cylinders; but this system is bad, and does not even effect the desired economy, because the passages, being narrow, impair the draught, and become speedily choked up with the soot, which would be burned profitably in a freer space; the decomposition also, being unequally performed, is less perfect, and the cylinders are more injured. It is better to make the flame envelope at once the body of the cylinder; after which it may circulate beneath the vault, in order to give out a portion of its caloric before it escapes at the chimney.

The fire should be briskly kindled, but lowered as soon as the distillation commences; and then continued moderate till the evolution of gas diminishes, when it must be heated somewhat strongly to finish the decomposition. The iron door is now removed, to extract the sulphate of soda, and to recommence another operation. This sulphate ought to be white and uniform, exhibiting in its fracture no undecomposed sea-salt.

Liquid muriatic acid has a very sour corrosive taste, a pungent suffocating smell, and acts very powerfully upon a vast number of mineral, vegetable, and animal substances. It is much employed for making many metallic solutions; and in combination with nitric acid, it forms the aqua regia of the alchemists, so called from its property of dissolving gold.

Table of Muriatic Acid, by Dr. Ure.

Acid of 120 in 100.	Specific gravity.	Chlorine.	Muriatic Gas.
100	1·2000	39·675	40·777
99	1·1982	39·278	40·369
98	1·1964	38·882	39·961
97	1·1946	38·485	39·554
96	1·1928	38·089	39·146
95	1·1910	37·692	38·738
94	1·1893	37·296	38·330
93	1·1875	36·900	37·923
92	1·1857	36·503	37·516
91	1·1846	36·107	37·108
90	1·1822	35·707	36·700
89	1·1802	35·310	36·292
88	1·1782	34·913	35·884
87	1·1762	34·517	35·476
86	1·1741	34·121	35·068
85	1·1721	33·724	34·660
84	1·1701	33·328	34·252
83	1·1681	32·931	33·845
82	1·1661	32·535	33·437
81	1·1641	32·136	33·029
80	1·1620	31·746	32·621
79	1·1599	31·343	32·213
78	1·1578	30·946	31·805
77	1·1557	30·550	31·398
76	1·1536	30·153	30·990
75	1·1515	29·757	30·582
74	1·1494	29·361	30·174
73	1·1473	28·964	29·767
72	1·1452	28·567	29·359
71	1·1431	28·171	28·951
70	1·1410	27·772	28·544
69	1·1389	27·376	28·136
68	1·1369	26·979	27·728
67	1·1349	26·583	27·321
66	1·1328	26·186	26·913
65	1·1308	25·789	26·505
64	1·1287	25·392	26·098
63	1·1267	24·996	25·690
62	1·1247	24·599	25·282
61	1·1226	24·202	24·874
60	1·1206	23·805	24·466
59	1·1185	23·408	24·058
58	1·1164	23·012	23·050
57	1·1143	22·615	23·242
56	1·1123	22·218	22·834
55	1·1102	21·822	22·426
54	1·1082	21·425	22·019
53	1·1061	21·028	21·611
52	1·1041	20·632	21·203
51	1·1020	20·235	20·796
50	1·1000	19·837	20·388
49	1·0980	19·440	19·980
48	1·0960	19·044	19·572
47	1·0939	18·647	19·165
46	1·0919	18·250	18·757
45	1·0899	17·854	18·349
44	1·0879	17·457	17·941
43	1·0859	17·060	17·534
42	1·0838	16·664	17·126
41	1·0818	16·267	16·718
40	1·0798	15·870	16·310
39	1·0778	15·474	15·902
38	1·0758	15·077	15·494
37	1·0738	14·680	15·087
36	1·0718	14·284	14·679
35	1·0697	13·887	14·271
34	1·0677	13·490	13·863
33	1·0657	13·094	13·456
32	1·0637	12·697	13·049
31	1·0617	12·300	12·641
30	1·0597	11·903	12·233
29	1·0577	11·506	11·825
28	1·0557	11·109	11·418
27	1·0537	10·712	11·010
26	1·0517	10·316	10·602
25	1·0497	9·919	10·194
24	1·0477	9·522	9·786
23	1·0457	9·126	9·379
22	1·0437	8·729	8·971
21	1·0417	8·332	8·563
20	1·0397	7·935	8·155
19	1·0377	7·538	7·747
18	1·0357	7·141	7·340
17	1·0337	6·745	6·932
16	1·0318	6·348	6·524
15	1·0298	5·951	6·116
14	1·0279	5·554	5·709
13	1·0259	5·158	5·301
12	1·0239	4·762	4·893
11	1·0220	4·365	4·486
10	1·0200	3·968	4·078
9	1·0180	3·571	3·670
8	1·0160	3·174	3·262
7	1·0140	2·778	2·854
6	1·0120	2·381	2·447
5	1·0100	1·984	2·039
4	1·0080	1·588	1·631
3	1·0060	1·191	1·224
2	1·0040	0·795	0·816
1	1·0020	0·397	0·408

MURIATES were, till the great chemical era of Sir H. Davy’s researches upon chlorine, considered to be compounds of an undecompounded acid, the muriatic, with the different bases; but he proved them to be in reality compounds of chlorine with the metals. They are all, however, still known in commerce by their former appellation. The only muriates much used in the manufactures are, Muriate of ammonia, or [Sal ammoniac]; muriated peroxide of mercury, [Mercury, bichloride of]; muriate of soda, or chloride of sodium, see [Salt]; muriate of tin, see [Calico-printing] and [Tin].

MUSK (Musc, Fr.; Moschus, Germ.), is a peculiar aromatic substance, found in a sac between the navel and the parts of generation of a small male quadruped of the deer kind, called by Linnæus, Moschus moschiferus, which inhabits Tonquin and Thibet. The colour of musk is blackish-brown; it is lumpy or granular, somewhat like dried blood, with which substance, indeed, it is often adulterated. The intensity of its smell is almost the only criterion of its genuineness. When thoroughly dried it becomes nearly scentless; but it recovers its odour when slightly moistened with water of ammonia. The Tonquin musk is most esteemed. It comes to us in small bags covered with a reddish-brown hair; the bag of the Thibet musk is covered with a silver-gray hair. All the analyses of musk hitherto made, teach little or nothing concerning its active or essential constituent. It is used in medicines, and is an ingredient in a great many perfumes.