:82 



NA TURE 



\_August 1 6, 1888 



by one volume of the gas at the temperature of the observation. 

 The next important observations were those of Fernet, published 

 in 1855 and 1857. He expelled the greater part of the gas of 

 the blood (dog) by passing through it a stream of hydrogen and 

 then submitting it to the action of the air-pump. He then intro- 

 duced into the apparatus the gas under a given pressure, the 

 absorption coefficient of which he had to determine. He then 

 estimated the amount of gas absorbed, under different pressures, 

 and found in the case of oxygen that the amount absorbed with 

 gradually decreasing increments of pressure was greater than 

 what would have been the case had it been in accordance with 

 Dalton's law of pressures. The oxygen was not then simply 

 dissolved in the blood. Further, Fernet arrived at the conclusion 

 that the greater portion of the oxygen was in a state of combina- 

 tion, whilst a small amount was simply dissolved according to 

 Dalton's law. 



It is evident, then, that while the amount of oxygen absorbed 

 varies with the pressure, it does not do so according to Dalton's 

 law. The amount decreases slowly with pressures below atmo- 

 spheric pressure, and it increases very rapidly with pressures 

 above it. It is when the pressure in the vacuum is as low as 

 one-thirtieth of an atmosphere that the oxygen is given up, and this 

 will be about the pressure of the aqueous vapour in the apparatus 

 at the temperature of the room, when the experiment is made. 

 The view that something in the blood is chemically united to the 

 oxygen is strengthened by the fact that serum does not absorb 

 much more oxygen than water can absorb, so that blood at a 

 temperature of 30 C. would contain only about 2 volumes per 

 cent, of oxygen gas were the latter simply dissolved in the fluid. 

 It can also be shown that defibrinated blood takes up oxygen 

 independently of the pressure, and that the quantity of oxygen 

 taken up by defibrinated blood is about equal to the quantity 

 absorbed by a solution of pure haemoglobin containing as much 

 of that substance as exists in the same volume of blood. 



By similar experiments made with carbonic acid, Fernet 

 determined that the greater portion of it was in a state of loose 

 chemical combination, whilst a small amount was simply dissolved 

 according to the law of pressures. Experiments with blood serum 

 showed similar results as regards carbonic acid, with the differ- 

 ence that the coefficient of absorption for oxygen was much less 

 than with ordinary blood. He therefore concluded that nearly 

 the whole of the carbonic acid was chemically retained in the 

 fluid of the blood, whilst nearly the whole of the oxygen was 

 combined with the red blood corpuscles. He then proceeded to 

 investigate whether or not the three principal salts of the blood, 

 carbonate of soda, phosphate of soda, and chloride of sodium, 

 in any way influenced the absorption coefficient of carbonic acid. 

 He found (1) that the addition of these salts to distilled water in 

 the proportion in which they exist in the serum slightly diminishes 

 the absorption coefficient ; (2) that chloride of sodium has no 

 influence on the absorption coefficient ; and (3) that carbonic 

 acid combines with the carbonate and phosphate of soda. 



In the same year (1855) Lothar Meyer published the results 

 of a series of researches of the same nature. Under the direction 

 of Bunsen, the blood was diluted with ten times its bulk of water, 

 and the gases were collected by boiling the liquid in vacuo at a 

 very gentle heat ; a certain amount of gas was thus obtained. 

 He also found that blood absorbs a much larger quantity of 

 carbonic acid than pure water at the same temperature, and stated 

 that when blood was exposed to oxygen at various pressures the 

 quantity of that gas taken up might be regarded as consisting of 

 two portions, one following Dalton's law and the other independent 

 of it. 



Further researches of a similar kind have been carried out by 

 Setschenow, Ludwig, Alexander Schmidt, Bert, Pfluger, and 

 others, and ingenious methods of collecting and of analyzing the 

 gases have been devised. To Prof. Pfluger and his pupils, in 

 particular, are we indebted for the most complete series of gas 

 analyses on record. The result has been to enable us to give 

 the average composition of the gases of the blood as follows. 

 From ico volumes of dog's blood there may be obtained — 



Oxygen. 



Arterial 18*4 to 22 6, mean 20 

 Venous < Mean 11*9 



Carbon ic A cid. Nitrogen. 



30 to 40 I - 8 to 2 



43 to 48 I - 8 to 2 



the gases being measured at 0° C. and 760 mm. pressure. The 

 venous blood of many organs may contain less than 1 1 '9 per cent. 

 of carbonic acid, and the blood of asphyxia may contain as little 



as 1 volume per cent. It is clear, then, that the gases of the 

 blood do not exist in a state of simple solution, but that they are 

 largely combined with certain constituents of the blood. Take, 

 for example, the case of oxygen. Berzelius showed long ago 

 that 100 volumes of water will absorb, at a given temperature 

 and pressure, 2 9 volumes of oxygen ; while, in the same cir- 

 cumstances, 100 volumes of serum will absorb 3*1 volumes, and 

 ico volumes of blood will absorb 96 volumes. Something in 

 the blood must have the power of taking up a large amount of 

 oxygen. 



( To be continued. ) 



THE BATH MEETING OF THE BRITISH 

 ASSOCIA TION. 



THE arrangements for the Bath meeting of the British Associa- 

 -*- tion are now practically completed. The Reception Room, 

 adjoining the Assembly Rooms, will be opened on Monday, 

 September 3, at 1 p.m., and on each succeeding week-day till 

 Thursday, September 13, at 8 a.m. precisely ; on Sunday, Sep- 

 tember 9, from 8 to 10 a.m., and from 3 to 6 p.m. In this 

 building will be the offices of the General and Local Secretaries 

 and Treasurers, a post office, telegraph office, telephone, ticket 

 office, lodgings, inquiry, excursion, and lost property offices, 

 and offices for the supply of all official papers and programmes. 

 There will also be lavatories, cloak-rooms, &c, &c. The 

 Council of the Association will meet in the Guildhall. 



In the Reception Room there will be offices for supplying 

 information regarding the proceedings of the meeting. The 

 tickets contain a map of Bath, and particulars as to the rooms 

 appointed for the Sectional and other meetings. A list of 

 lodgings, or apartments, with prices, &c, and also information 

 concerning hotels, and other similar matters, will be furnished 

 by the Lodgings Clerk between the hours of 9 a.m. and 6 p.m. 

 daily, at No. 13 Old Bond Street, up to I p.m. on Monday, 

 September 3, and after that time at the Reception Room between 

 the same hours daily. 



The places of meeting, &c, will be in the Assembly Rooms, 

 the Drill Hall, and the Guildhall. The Secretaries of Sections 

 will be lodged at the White Lion Hotel. The following are the 

 Section Rooms : — A, Mathematics, St. James's Hall ; B, 

 Chemistry, Friends' Meeting House ; C, Geology, Mineral 

 Water Hospital ; D, Biology, Mineral Water Hospital ; E, 

 Geography, Guildhall ; F, Statistics, Christ Church Hall ; G, 

 Mechanics, Masonic Hall ; H, Anthropology, Grammar School ; 

 Sub-Sections C and D, Blue-Coat School. 



By the courtesy and liberality of the Directors of the Western 

 Counties and South Wales Telephone Company, the whole of 

 the Section Rooms will be telephonically connected with the 

 Reception Room, and, through the Telephone Exchange, with 

 all important places in the neighbourhood, free of any expense 

 to the Local Executive Committee, or members and associates, 

 for the meeting. 



The first general meeting will be held on Wednesday, 

 September 5, at 8 p.m. precisely, in the Drill Hall, when Sir 

 H. E. Roscoe, M.P., F.R.S., will resign the chair, and Sir 

 Frederick Bramwell, F.R.S., President- Elect, will assume the 

 Presidency, and deliver an address. According to the Times, 

 Sir Frederick is sure to deal pretty largely with progress in the 

 department with which his name is so eminently connected. 

 With regard to the addresses of the Presidents of Sections the 

 Times makes the following statement : —In Section A (Mathe- 

 matics and Physics), Prof. Fitzgerald is President, and the 

 subject of his address willj probably be connected with Clerk- 

 Maxwell's theory that electric and magnetic forces are produced 

 by the same medium that propagates light, and some recent 

 experimental proofs of that theory. In Section B (Chemistry), 

 Prof. W. A. Tilden, of Birmingham, is President, and his 

 address will be concerned with the history of the teaching ot 

 chemistry practically, and will review the existing provision for 

 efficient teaching of chemistry in this country. This will be 

 followed by some discussion of the methods actually used or pro- 

 posed for teaching chemistry either as a constituent part of a 

 liberal education or for technical purposes, together with an 

 endeavour to trace the causes of the unproductiveness of the 

 English schools in respect to advanced studies, and especially in 

 regard to the results of original resexrch. Prof. Boyd Dawkins 



