72 REPORT — 1872. 



tific man, of Ligli culture, in early years a distinguished surgeou, and till recently 

 medical adviser at the Court of Copenhagen. He believed tliat all neutral fats 

 were composed of minute globules of fatty matter, each one of which was encased 

 in an envelope of a substance which he termed albumen (in the proportion of 1 to 

 2 per cent, of the whole fat), the existence of which could be demonstrated by dis- 

 solving the fat in ether or benzole, and precipitating the solution with water, when 

 the albuminous matters collected at the plane of junction of the water and the fatty 

 solution. In his opinion, the excess of alkali, or of heat, or of pressure, necessary 

 to decompose a neutral fat, was required to destroy this albumen, with which were 

 associated many of the colouring-matters. By the use of certain oxidizing agents, 

 the envelopes of the globules composing neutral fat could be disintegrated, and sub- 

 sequently oxidized, so that their specific gravity was increased, and they could then 

 be removed by mere subsidence, leaving the fatty acids comparatively free from 

 coloui". 



In practice, the tallow, heated to llo° C. in an open vat, is well agitated with 

 G per cent, sulphuric acid for a short period, by which the albuminous envelopes 

 are charred ami broken up. Water is then added, and the blackened but still 

 nadral fiit boiled with it. Decomposition of the fat f/radually takes place, the 

 degree of it being judged of by the mode of crystallization of the fatty acids, 

 when it is complete, the water is run off, and the glycerine which it contains 

 is purified from sulphuric acid by precipitation of the latter with lime, and concen- 

 trated for sale. The blackened fatty acids are then subjected to the action of a 

 solution of one or more of the following oxidizing agents — sulphuric, nitric, and 

 hydrochloric acids, bichromate and permanganate of potash, and hypochlorite of 

 lime. The albuminous matters coagulate together, and increase so much in specific 

 gravity, that they subside in a few hours, leaving the fatty acids of a pale brown 

 colour. These acids are then washed, ciystallized, and subjected to cold and hot 

 hydraulic pressing in the usual manner. Tlie products are a stearic acid whiter, 

 harder, and greater in quantity per ton of tallow than that obtained by any other 

 method, and elaidic acid superior to that made in any other way. The iluthor of 

 the paper was engaged in extending the invention to vegetable fats. He illustrated 

 the paper with specimens from Copenhagen (sent expressly for the Meeting) and 

 from his own factory. 



On the Mode of Collection of Samjdes of Deep-sea Water, and of their Analysis 

 for dissolved Gaseous Constituents, employed on hoard H.M.S. ^Poraipine ' 

 during the Smnmers of 1S69 and 1870. Bii Willi.vm L.4.NT Caepentee, 

 B.A., B.Se., F.C.S. 



The object of the paper was to obKiin a discussion on the subject, in the hope 

 that a method might be suggested more free from error, and as readily adaptable 

 to the exigencies of shipboard as those hitherto employed. The author was the 

 first to adapt the late Prof. W. A. Miller's method to this purpose ; and many of 

 the results arrived at had been published in the ' Proceedings of the Royal Society ' 

 issued in 1870. The samples of water were collected by a cjdinder furnished with 

 valves opening upwards, which was fastened to the sounding-line. When used 

 with certain precautions, it was believed that this instrument, simple as it was, left 

 little to be desired. The method of analysis consisted essentially in boiling about 

 750 cub. centims. of the sea-water in a vacuum, and collecting the gas over mercurv^, 

 absorbing the carbonic acid and oxygen with the usual reagents. Unless the 

 duplicate analyses agreed closelj', they were rejected. The average total quantity 

 of dissolved gas was 2-8 vols, per 100 vols, of water. At the surface 20 to 25 per 

 cent, of this was carbonic acid; but close to the bottom, at great depth.?, this per- 

 centage increased very largely, amounting to above 65 per cent, in one case. 



In the more northern latitudes the proportion of oxygen was greater, and of car- 

 bonic acid less, both in surface- and bottom-water, than in the more southern. 



The author then stated that there was a very generally received opinion that the 

 water at great depths contained so great an excess of dissolved gas, that when it 

 was brought to the surface, and the pressure thus removed, the gas escaped with 



