128 Proceedings of the British Association. 



From a number of experiments on the elimination of carbonic acid 

 during respiration, he arrived at the following results : — that 266.66 

 cubic feet of atmospheric air pass through the lungs of an adult in 

 twenty-four hours, of which 10.666 are converted into carbonic acid, 

 yielding 5.45 ounces of carbon, or 124.628 pounds annually, which 

 will give a total of 147.070 tons of carbon as the annual product of the 

 inhabitants of Great Britain and Ireland! The average amount of 

 carbonic acid found in atmospheric air in which animals had expired, 

 was found to be, for warm-blooded animals, 12.75 per cent., for the 

 cold-blooded animals, 13.116 per cent. When the animals were remov- 

 ed, on becoming comatose, the average amount of carbonic acid was 

 found to be 10.42 per cent. On confining a taper until its extinction, 

 the quantity of carbonic acid found was 3.046 per cent. From hence it 

 would appear, that an atmosphere that has ceased to support combus- 

 tion can support animal life for some time, which Mr. Coathupe proved 

 by direct experiment. 



Dr. Costello presented a report of ten cases of Calculus treated by 

 Lithotrity. The patients were of ages between fifty-three and seventy- 

 six, the stones varying in size from that of a pigeon's egg to that of a 

 hen's egg. The lithotrite was successively applied at sittings of from 

 thirty to fifty seconds. Dr. Costello strongly insisted on the necessity 

 of this point, especially at the commencement of the treatment, as the 

 constitution is thus saved from the shock and re-action which follow 

 protracted operation. One of the cases was remarkable : the collected 

 fragments of the removed calculus were shown to the Section ; they 

 filled a bottle capable of containing at least four fluid ounces. The 

 patient had suffered upwards of ten years ; during the treatment he su- 

 perintended the farming of his estate as usual, without any inconveni- 

 ence ; the entire of the ten cases were cured, bearing high testimony to 

 the value of this improvement in operative surgery. In connexion 

 with these operations, Dr. Costello related an incident which, to use his 

 own words, " exemplified the progress of surgery and steam travel- 

 ling," — he operated on three patients residing in three different coun- 

 ties, and travelled over a space of upwards of 200 miles in eighteen 

 hours. 



Mr. Nasmyth read a paper ' On the Microscopic Structure of the 

 Teeth,' in which he treated also of the covering of the enamel and of 

 the organization of the pulp. He first stated that his researches had 

 led him to a conviction contrary to that of Retzius, Purkinje, and 

 Frankel, for he had found that the enamel in all cases, possesses a dis- 

 tinct envelope or coating. On the incisor of the calf, and on several 

 other simple teeth, he had also traced in it the corpuscles of Purkinje, 

 analogous to those found in bone.* With respect to the microscopic 



* A full description of this structure will be found in a paper by Mr. Nasmyth, 

 in the forthcoming volume of the Transactions of the Medico-Chirurgical Society, 

 accompanied by drawings. 



