I. 47175 grm. of substance gave 1245 of gold. III. 309 grm. of substance gave 495 of carbonic acid and 101 of water. Percentage composition :- The formula, C, H, N, H AuCl, requires the following percentages :— 27 24 Hydrobromate of Mauveine.-This salt is prepared in a similar manner to the hydrochlorate, which it very much resembles, except that it is less soluble in alcohol. Analysis of preparations dried at 100° C. gave the following numbers :-- 1515 of bromide of silver. I. 3935 grm. of substance gave II. 450 grm. of substance gave III. 3265 grm. of substance gave 79675 of carb. acid and ⚫158 of water. IV. 35125 grm. of substance gave 86075 of carbonic acid and ⚫1675 of water. These numbers agree with the formula C, H, NH Br, as shown by the comparisons in the following Table : Hydriodate of Mauveine.-In preparing this salt from the base, it is necessary to use hydriodic acid which is colourless, otherwise the free iodine will slowly act upon this salt. It crystallizes in prisms having a green metallic reflexion. It is more insoluble than the hydrobromate. The products used in the subjoined analysis were recrystallized three times, and dried at 100° C. The formula, C1 H24 N, HI, requires the following values: 27 Acetate of Mauveine.-This salt is best obtained by dissolving the base in boiling alcohol and acetic acid. On cooling, it will crystallize out; it should then be recrystallized once or twice. This acetate is a beautiful salt, possessing the green metallic lustre common to most of the salts of mauveine. Two combustions of specimens dried at 100° C. gave the following numbers :— I. 28325 grm. of substance gave 778 of carb. acid and ⚫153 of water. II. 29275 grm. of substance gave '806 of carb. acid and 1645 of water. Percentage composition : Carbon Hydrogen I. II. These numbers lead to the formula C2 H2 N, O, C17 H2 N1, C, H, O,, 29 as shown by the following Table : 27 24 Carbonate of Mauveine.-The tendency of solutions of mauveine to combine with carbonic acid is rather remarkable. If a quantity of its solu tion be thrown up into a tube containing carbonic acid over mercury, the carbonic acid will quickly be absorbed, the solution in the mean time passing from its normal violet colour to purple. To prepare this carbonate, it is necessary to pass carbonic acid gas through boiling alcohol containing a quantity of mauveine in suspension. It is then filtered quickly, and carbonic acid passed through the filtrate until nearly cold. On standing, this liquid will deposit the carbonate as prisms, having a green metallic reflexion. A solution of this salt, on being boiled, loses part of its carbonic acid and assumes the violet colour of the base. When dry this carbonate rapidly changes, and if heated to 100° C. loses nearly all its carbonic acid and changes in colour to a dull olive; therefore, as it cannot be dried without undergoing a certain amount of change, its composition is difficult to determine. However, I endeavoured to estimate the carbonic acid in this salt by taking a quantity of it freshly prepared and in the moist state, and heating it in an oil-bath until carbonic acid ceased to be evolved. The residual base was then weighed, and also the carbonic acid, which had been collected in a potash bulb, having been previously freed from water by means of sulphuric acid. The following results were obtained :— I. 1.88 residual base obtained; 190 carbonic acid evolved. II. 1.375 residual base; 1385 carbonic acid evolved. 190 of CO, is equal to 268 of H,CO,; this, added to the residual base, will give the amount of substance experimented with, viz. 2.148. The amount of CO, obtained from this quantity, therefore, is 8.8 per cent. Calculating the second experiment in a similar manner, the amount of carbonate operated upon would be 1.5702 grm.; the percentage of CO, obtained is therefore equal to 8.8. A carbonate having the formula (C27 H2 N ̧), H, CO, would contain 5.1 per cent. of CO,, and an acid carbonate having the formula O2, H, N., H, CO, would contain 9.4 per cent. of CO,. 27 24 27 Considering that this salt when prepared begins to crystallize before it is cold, probably the first portions that deposit are a monocarbonate, while the larger quantity which separates afterwards is an acid carbonate. Hence the deficiency in the amount of CO, obtained in the above experiments. I hope to give my attention to this remarkable salt at a future period. In the analysis of the salts of mauveine great care has to be taken in drying them thoroughly, as most of them are highly hygroscopic. I am now engaged in the study of the replaceable hydrogen in mauveine, which I hope will throw some light upon its constitution. From its formula I believe it to be a tetramine, although up to the present time I have not obtained any definite salts with more than 1 equiv. of acid. When mauveine is heated with aniline it produces a blue colouring matter, which will doubtless prove to be a phenyle derivative of that base. A salt of mauveine when heated alone also produces a violet or blue compound. These substances I am now examining, and hope in a short time to have the honour of communicating them to the Society. April 7, 1864. Major-General SABINE, President, in the Chair. The Rev. Dr. Salmon was admitted into the Society. The following communications were read : I. "On the Functions of the Cerebellum." By WILLIAM HowSHIP DICKINSON, M.D. Cantab., Curator of the Pathological Museum, St. George's Hospital, Assistant Physician to the Hospital for Sick Children. Communicated by Dr. BENCE JONES. Received March 8, 1864. (Abstract.) The paper is divided into two Parts; the first gives the results of experiments on animals; the second, of observations upon the human being. PART I. Assuming that the great divisions of the brain preserve each the same function through the vertebrate kingdom, it is maintained that experiments which can be performed only on such of the lower animals as are very tenacious of life, will afford deductions of universal application. The method of proceeding with regard to each species was to remove, first, the whole encephalon, with the exception of the medulla oblongata ; then in a similar animal only the cerebrum was taken away. The only difference between the two cases was in the fact that one animal had a cerebellum, and the other had not. A comparison was believed to show, in the powers which one had more than the other, the function of the organ the possession of which constituted the only difference. Finally it was ascertained in each species what is the effect of taking away the cerebellum alone. The use of the organ was thus estimated in two ways-by the effect of its addition to the medulla, and of its subtraction from the rest of the nervous system. The species so treated are arranged in an ascending scale, according to the comparative weight of the cerebellum. The field-snake, frog, salamander, toad, land-tortoise, eel, water-tortoise, pike, perch, tench, dace, carp, gold-fish, rudd, loach, and gudgeon were subjected to these operations; besides which, many experiments of a less systematic character were made upon birds and mammalia. The results are these: In Reptiles, with the exception of the snake, the cord, together with the medulla oblongata, is sufficient to give the power of voluntary or spontaneous motion--limited, but usually enough to allow of feeble locomotion. With the addition of the cerebellum, all actions dependent on the will appear to be naturally performed. VOL. XIII. P The removal of the cerebellum shows that the cerebrum by itself is unable to give more than a limited amount of voluntary motion, and that of a kind deficient in balance and adjustment. It is therefore inferred that the cord, together with the medulla oblongata, is a great source of spontaneous motor power, in which function both the cerebrum and the cerebellum take part, the cerebellum to the greater extent; it also appears that a certain harmony in the use of the muscles depends on the possession of the latter organ. Regarding Fishes, the cord and medulla oblongata seem unequal to the performance of voluntary motion. When the cerebellum is added, the powers become so far extended that movements are made in obedience to external stimuli. Generally speaking, a determined position is maintained and locomotion accomplished, without the use, however, of the pectoral fins. If the cerebellum only be taken away, there is a loss of the proper adjustment between the right and left sides; so that oscillation or rotation takes place. All the limbs are used, but apparently with a deficiency of sustained activity. It is therefore concluded that with Fishes, as with Reptiles, the power of intentional movement is shared by both cerebrum and cerebellum; the former in this case has the larger influence. Such movements as depend on the cerebrum are destitute of lateral balance, are sudden in being affected by any external cause, and are emotional in their character. Such as depend on the cerebellum are mutually adjusted, of a continuous kind, and less directly under the influence of consciousness. : The same facts were supported by experiments on the higher orders of animals in these it seemed that the cord and medulla are insufficient to excite voluntary movements. The muscles, as with fishes and reptiles, acknowledge a double rule, from the cerebrum and from the cerebellum. The anterior limbs are most subservient to the cerebrum; the posterior to the cerebellum. The limbs on one side are in connexion chiefly with the lobe of the opposite side. The absence of the cerebellum destroys the power of lateral balance. From the negative results of the experiments, it is inferred that the cerebellum has nothing to do with common sensation, with the sexual propensity, with the action of the involuntary muscles, with the maintenance of animal heat, or with secretion. The only function which the experiments assigned to the cerebellum is such as concerns the voluntary muscles, which receive therefrom a regu lated supply of motor influence. Each lateral half of the cerebellum affects both sides, but the one opposite to itself most. The cerebellum has a property distinct from its true voluntary power, which harmonizes the action of the voluntary muscles, and has been described as "coordination." |