85 



an outer crust stained with oxide of iron, and if a section was taken of one of 

 them it would be found to look very much like a sponge, and certainly appeared 

 to be organic. 



Mr, Lowne said he must strongly demur to the assertion that any structure 

 found in an inorganic substance, and not of a crystalline nature, was therefore 

 organic ; and also that they were to draw a line and say that all crystalline sub- 

 stances were inorganic, and all others which showed any apparent structure 

 were organic. It was not any one who had not worked at these subjects who 

 must see them, but they must be seen and examined by an adept in the subject, 

 and it must be pointed out by him why they were to be regarded as organic. 



The President said he went to a certain extent with Mr. Johnson in regarding 

 it as a high probability that these structures were organic ; it was, however, a 

 pity that he had not fortified his case by bringing his specimens. He thought 

 it must not be overlooked that silica deposited in a coloured state sometimes 

 bore the closest resemblance to organic structure ; nor that silica existed in 

 nature in solution, and that there were agencies in nature other than organio 

 by which it was deposited. He would refer them for further illustration of thi3 

 subject to the Cantor lectures by Dr. Calvert. 



Mr. Lowne said what he wanted to know was, why were these structures 

 organic P 



Mr. Johnson said he should like to refer to some experiments which he had 

 been making with silica in solution. First of all he took some tadpoles and put 

 them into nitric acid — in half-an-hour they were completely disintegrated, and 

 in an hour there was very little tadpole left. He then put some more tadpoles 

 into a solution of silicate of soda, and left them there for three or four days • he 

 then took them out and washed them to remove all superfluous solution of 

 silicate, and then placed them in a vessel with a small quantity of water. To 

 this he added a drop or two of nitric acid, and generally increased the quantity 

 until it was entirely acid. The tadpoles were left in this for weeks, and they 

 remained all the time in just the same condition as when first put in, and from 

 this he argued that some very important change must have taken place. They 

 knew, as a fact, that there was a large class of bodies in which silicon occupied 

 an analogous place, and it seemed to him highly probable that there might bo 

 some process by which the one substance was exchanged for the other. 



Mr. Lowne said he should much like to have the subject cleared up. He 

 thought that in the tadpole case there would be found a source of ultimate error 

 in the dilution of the nitric acid. For a very small quantity of water in nitric 

 acid when brought into connection with soda would cause nitrate of soda to bo 

 formed, and this was really non-corrosive. If, however, there was really a sub- 

 stitution of silicon for carbon, a most important discovery had been made. He 

 hoped this could be clearly shown. 



Mr. Johnson said the acid was diluted in the one case exactly the same as it 

 was in the other. 



The President considered that Mr. Johnson had made out a very strong 'prima 

 facie case. He quite believed in the possibility of these substances having an 

 organic structure, but until they had some opportunities of further examination 

 they could do very little more in the way of coming to a conclusion. 



Six gentlemen were then proposed for membership, the meetings and excur- 

 sions for the ensuing month were announced, and the proceedings terminated 

 with a conversazione, at which the following objects were exhibited : — 



