SPEEMACETI 869 



C of Brewster's spectrum; it is not easy to determine accurately with which 

 of the dark lines this yellow line is coincident. Strontium gives six red, one 

 orange, and one blue line. Calcium and its salts, a bright green lino, an intensely 

 bright orange line, and the paler intermediate bands. Barium gives well-defined 

 green lines, some yellow lines, varying in intensity, an orange line, and indications 

 of red. 



Incandescent gases and vapours give off light of certain definite degrees of re- 

 frangibility, or they furnish spectra consisting of certain fixed lines ; and those 

 incandescent gases or vapours absorb light of the same degree of refrangibility as that 

 which they emit. This is (reasoning by analogy) only the expression in relation to 

 light of the celebrated statement made in regard to sound, that a body absorbs all the 

 oscillations which it can propagate. 



Spectrum analysis has been applied with success to determine the moment when in 

 the process of making steel by the Bessemer process the whole of the carbon is exhausted. 

 For a full account of Spectrum Analysis, see Watts's ' Dictionary of Chemistry.' 



SPECUS/USS XVIETAIi. The metal employed in the mirrors of reflecting 

 telescopes. The late Earl of Eosse, who was eminently successful in the production 

 and polishing of large specula, says, in his paper published in the Transactions of 

 the Royal Society, ' Tin and copper, the materials employed by Newton in the first 

 reflecting telescope, are preferable to any other with which I am acquainted, the best 

 proportions being 4 atoms of copper to one of tin, in fact, 126'4 parts of copper to 

 58'9 of tin.' 



Mr. Eoss remarks that when the alloy for speculum metal is perfect, it should be 

 white, glassy, and flaky. Copper in excess imparts a reddish tinge, and when tin is in 

 excess the fracture is granulated and less white. Mr. Eoss pours the melted tin into 

 the copper when it is at the lowest temperature at which a mixture by stirring can be 

 effected ; then he pours the metal into an ingot, and, to complete the combination, 

 remelts it in the most gradual manner, by putting the metal into the furnace almost 

 as soon as the fire is lighted. Trial is made of a small portion taken from the pot 

 immediately prior to pouring. 



SPEISS. A compound of nickel, arsenic, and sulphur, containing small quantities 

 of cobalt, copper, and antimony ; it is found at the bottom of crucibles in which smalt 

 is manufactured. See COBALT. 



SPELTER or SPEXiTiOTBE. See ZINC. 



SPS3&1V1 ACBTI ; the Celine of Chevreul. In certain species of the cachalot whale, 

 as the Physeter macrocephalus, and the tursio, microps, and orthodon, as also the Del- 

 phinus cdcntulus, the fat of some parts of their bodies contains a peculiar substance, 

 called spermaceti. The head is the principal part from whence it is obtained. In the 

 right side of the nose and up.per surface of the head of the whale, is a triangular- 

 shaped cavity, called by the whaler's, ' the case.' Into this the whalers make an 

 opening, and take out the liquid contents (oil and spermaceti) by a bucket. 



The dense mass of cellular tissue beneath the case and nostril, and which is techni- 

 cally called the 'junk," also contains spermaceti, with which and oil its tissue is 

 infiltrated. The spermaceti from the case is carefully boiled alone and placed in 

 separate casks, when it is called ' head matter.' This ' head matter ' consists of 

 spermaceti and oil. For the purpose of separating the spermaceti from the oil, it is 

 cooled, when the spermaceti congeals, and is separated by being thrown into large filter 

 bags, when the oil filters through, leaving the spermaceti behind ; the solid thus 

 obtained is subjected to compression in hair-bags, placed in an hydraulic press. It 

 is then melted in water, and the impurities skimmed off. Then it is remelted in a 

 weak solution of potash to remove the last particles of oil, washed in water, and fused 

 in a tub by the agency of steam, laded into tin pans, and allowed slowly to copl, when 

 it forms a white, semi-transparent, brittle, lamellar, crystalline mass. Commercial 

 spermaceti usually contains a minute portion of sperm oil, which may be removed by 

 boiling with alcohol ; the spermaceti dissolves and again separates on cooling, in order 

 to obtain it perfectly pure, this process must be repeated until the alcohol separates no 

 more oil. 



When absolutely pure, spermaceti is a white laminated substance, without taste, and 

 most odourless, and in this case it is called cetine. By the addition of a few drops 

 of alcohol or almond oil, it may be powdered. At 60 its sp. gr. is 0'943. Itmelts 

 at 120, and at 070 may be sublimed unchanged. It is insoluble in water, slightly 

 soluble in alcohol, and much more so in ether ; it is also soluble in the fatty and 

 volatile oils, and if the solution be saturated when hot, the greater part of the sper- 

 maceti separates on cooling. 



Spermaceti is only saponified with difficulty, in which process it is separated into 

 two distinct substances : one, G^IP'O 2 (C^K^'O), belonging to the series of alcohols, 

 is called cctylic (cthalic) a/cc/tc^; and the other cctylic (cihalic} acid^ C'-U^O 1 (C H 3:: O 2 }; 



